Citrix Virtual Desktop Handbook

Citrix
Virtual Desktop Handbook
Version 5.x

Prepared by:
Worldwide Consulting Solutions

Citrix Virtual Desktop Handbook

TABLE OF CONTENTS
Section 1: Overview .................................................................................................... 2
Introduction ................................................................................................................ 4
Methodology ............................................................................................................... 5
Project Plan ................................................................................................................ 8
Section 2: Assess ....................................................................................................... 4
Business Drivers ...................................................................................................... 10
Data Capture ............................................................................................................. 11
User Segmentation................................................................................................... 19
Application Assessment .......................................................................................... 24
Project Management ................................................................................................ 31
Section 3: Appendix ................................................................................................. 39
Glossary and Abbreviations .................................................................................... 40
Revision History ....................................................................................................... 41
Authors ..................................................................................................................... 41


SECTION 1: OVERVIEW


Introduction
If you read industry magazines, you would think desktop virtualization is an impossible technology to
deploy. So why do it? The simple answer is that Desktop Virtualization is designed to make your work life
more flexible and mobile. A flexible work life can mean different things to different people: any device, any
place, and any time. The “any-ness” of the work life means that a user becomes mobile. They can work
on any endpoint device, can work from any location, and can work at any time they choose as long as
they get their work done. Desktop virtualization provides flexibility without complicating the user’s life or
putting corporate data at risk.
Take the following response from a desktop virtualization user:

Experiences from the Field
As a remote employee for [company], I struggled every time I needed to access the company’s
intranet, which forced me to VPN into the network. I also kept data on my local device because trying
to access it over my broadband connection was too slow. Some coworkers did the same and lost data
due to a virus, thankfully I was luckier.
Depending on my mood (and the weather), changing devices and locations was a challenge as I had
to have my applications and data copied to many different endpoints. I know this was unsecure, but I
didn’t care because I was more concerned with flexibility.
Since moving to a virtual desktop, I’m able to use any device. I’m able to work from any location. And
best of all, I don’t have to worry about copying my data and applications onto all of my personal
devices. I paid for these devices; I don’t want work to clutter up my personal space.

Unfortunately, many organizations struggle or fail to achieve this level of success within their user
community. Why does one organization succeeds while another organization struggles?
If we compare the factors between success and failure between desktop virtualization and other
technology related projects, we see that there is little difference:

 Lack of justification: Without a solid business reason, desktop virtualization is simply a new way
to deliver a desktop. A business justification gives the project team a goal to strive towards.

 Lack of a methodology: Many people who try and struggle to deploy a desktop virtualization
solution do so because they jump right in without understanding or implementing the appropriate
prerequisites. A structured methodology provides the path for the project.

 Lack of confidence: For many who embark on a desktop virtualization project, there is a lack of
experience, which creates a lack of confidence in the design. Architects begin to second guess
themselves and the project stalls.

Our hope is that this handbook can alleviate the anxiety associated with a desktop virtualization design by
showing how to tackle the challenges in a manner that is technically sound, but also feasible and effective
for organizations facing deadlines and other organizational challenges.
The Citrix Virtual Desktop Handbook examines the project lifecycle for a desktop virtualization project.
The Handbook provides the methodology, experience and best practices needed to successfully design
your own desktop virtualization solution. However, this handbook is not the only resource to guide you
through your desktop virtualization journey. Citrix also provides Project Accelerator; an interactive online
tool creating customized sizing and design recommendations based on the methodology, best practices
and expert advice identified within this handbook.
Note: This is Phase 1 for the Citrix Virtual Desktop Handbook focusing on Assess. Phase 2 and beyond
will provide design, deploy and maintain guidance.

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Methodology
The Citrix Virtual Desktop Handbook follows the Citrix Consulting Methodology. A proven methodology
that has been successfully employed across thousands of desktop virtualization projects. Each phase
includes guidance on the important questions to ask, what tools to use, and tips to help you succeed.
The Citrix Consulting Methodology consists of four phases:

Assess Design Deploy Maintain

Figure 1: Citrix Consulting Methodology

Assess
The Assess phase identifies information necessary for the design:
1. Business Drivers: Documents and prioritizes the motivation and key drivers behind the
desktop virtualization initiative so that the project team can focus their efforts on creating a
solution which meets the needs of the business.
2. Data Capture: Data is collected on users, applications, devices and infrastructure. This
information will be used to segment users, identify risks and determine current capabilities.
3. User Segmentation: Users are divided up into groups based on a common set of
requirements so that an appropriate FlexCast model can be assigned to each one without
compromising on performance or functionality.
4. Application Assessment: The application list is rationalized by removing legacy applications,
standardizing application versions, and removing non-business applications. The remaining
applications are then analyzed for compatibility issues.
5. Roadmap: Each user group is prioritized by comparing implementation time against business
impact. The results of this prioritization process are then used to update the project plan. The
project team is defined according to the skillsets required.

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Design
The design phase focuses on a five-layer approach to ensure than all key design decisions are
considered:
1. User Layer: The user layer documents the recommended end points and the required user
experience functionality.
2. Access Layer: This layer shows how the user layer will connect to their desktop, which is
hosted in the desktop layer of the architecture. Local users will often connect directly to
StoreFront while remote users often connect via a set of firewalls that protect the internal
environment. To bridge the firewalls, remote users will often connect with an SSL-VPN device
(like Citrix Access Gateway). Finally, for disconnected users using Citrix XenClient, they will
need to synchronize their local images with the backend store, requiring additional access
through the set of firewalls separating the internal/external environments.
3. Desktop Layer: This layer contains the user’s virtual desktop, broken down into FlexCast
models. It is subdivided into three components: Image, Applications and
Personalization. Within each sub-layer, specifics are documented detailing the operating
system, assigned policies, and profile design and application requirements.
4. Control Layer: This layer is responsible for managing and maintaining all other layers. It
provides details on the controller requirements to support the entire solution. The Control
layer is broken up into Access Controllers, Desktop Controllers and Infrastructure Controllers.
The Access Controllers focuses on the hardware requirements to support the Access
Layer. The Desktop Controllers provide details on the components required to support the
desktop layer, which could include XenDesktop, XenApp, XenClient or Provisioning
Services. Finally, the Infrastructure Controllers are responsible for providing the underlying
resources to support each component. These resources can include databases, license
servers, and hypervisor controllers.
5. Hardware Layer: This layer is responsible for the physical devices required to support the
entire solution. It includes servers, processors, memory, storage devices. This layer is broken
into three groups focused on providing the necessary resources for specific parts of the entire
solution. One group of servers will support the XenApp (shared) components (if applicable). A
second group of servers will support the XenDesktop (VDI) components (if applicable). A final
group of servers will support the underlying infrastructure for the entire environment, which is
identified as the Control Layer.

Deploy
During the Deploy phase, FlexCast Infrastructure is installed and configured as described in the
design phase. All components of the infrastructure are thoroughly unit and regression tested before
users are provided with access to the environment.
A pilot is performed to ensure that all requirements are addressed in the deployment before it is rolled
out. In addition, the pilot helps determine scalability thresholds for the production environment. Key
success criteria should be identified for the pilot and tested by a subset of end users. Once the pilot is
complete, the solution is rolled out to production. Rollout includes technical assistance, deployment
work plans and end user and IT staff training.

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Maintain
The Maintain phase consists of four different activities:
1. Monitoring: After the virtual desktop environment has been designed and rolled out to
production, ongoing monitoring is required. Monitoring the new environment enables
administrators to address issues proactively. By having an in-depth understanding of current
and expected behavior of the various components, administrators are better equipped to
discover an issue before it impacts the user community. Furthermore the data tracked during
normal operations can be used for trending and capacity planning.
2. Support: When problems arise, technical support is the first point of contact for issue
resolution. This section addresses the proper staffing, organization, training, and tools utilized
in effective support organizations.
3. Testing and Change Control: Regular upgrades are required to ensure that the virtual
desktop environment is up to date. The change management processes ensures that all
improvements are properly approved, tested, and validated by appropriate parties. This
section covers the proper processes that ensure changes in production environments are
deliberate, proven, and accountable.
4. Ongoing Operations: Maintenance, issue prevention and resolution are core responsibilities
in running a Citrix infrastructure. When the responsibilities and assignments are structured
properly, friction is kept to a minimum, reducing issues and their resolution times. This section
discusses routine operations that Citrix environments require for optimal performance.

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Project Plan
A detailed, up-to-date project plan is vital to the success of the project. The project manager should use
the project plan to monitor costs, manage project staff, follow progress against milestones, and track key
dependencies such as hardware, storage, training, licenses and certificates so that they can be
addressed before they can become bottlenecks. The project plan should be regularly distributed between
project team members to ensure that everybody is aware of progress as well as remaining tasks.
At the start of the project, only plan for the Assess phase. You won’t be able to plan for the Design or
Deploy phases yet because you’ll need a better understanding of the FlexCast models, capabilities, user
groups and applications required. After the roadmap stage, update the project plan to include separate
design and deploy activities for each user group identified, ordered by priority. This will help to ensure
that the business receives maximum value from their investment as soon as possible and allow
infrastructure to be built out in manageable IT projects that minimize risk and maximize the chance for
project success.
A sample project plan, created in Microsoft Project 2010 format, accompanies this document. A high level
overview is shown below:

Figure 2: Sample Project Plan

Note: Some of the tasks in the project plan template have been scheduled to occur in parallel because it
is assumed that multiple project team members are available. All activities, resources and scheduling
within the sample project plan should be reviewed prior to starting your project.

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Business Drivers
The first step in your virtual desktop project should be to understand and prioritize the strategic
imperatives of the organization. This enables the project management team to define success criteria and
allows the design team to create a tailored and optimized architecture.
Requirements can be captured during meetings or by distributing questionnaires. Meetings are more time
consuming, but allow for follow-up questions to be asked and help to simplify the prioritization process. It
is important that this exercise be completed jointly by both business managers and IT decision makers
since both groups will have significantly different viewpoints. Take the following examples of what certain
organizations faced, which drove their selection of desktop virtualization.

Finance: A large financial institution had a base of operations in the city designated as the host city
for an upcoming G8 summit. As these types of meetings historically include riots, protests and other
issues that can disrupt business and the safety of their employees, the financial organization needed
an alternative allowing their users to work from the safety of their homes.
Agriculture: Due to thin margins, an agriculture organization wanted to save money by extending the
life of desktop PCs while still being able to run the latest applications.
Healthcare: A large healthcare organization was in need of a solution to simplify application updates
as the main application required updates on a weekly basis. Due to the distributed nature of the
endpoint devices, the organization was in need of a better application delivery solution.

These are just a few examples, but they demonstrate how organizations think about their priorities. Most
organization do not focus on technology, they focus on the needs of the user and of the organization.
These needs can be met with technical solutions but it is imperative the team understands the “Why” of
the project.
In addition to the three real world examples, the following table identifies a few other priorities often stated
from many organizations:

Requester Requirement
Business Managers Better IT Agility: Flexible desktop solution that is capable of accommodating periods of
change such as rapid growth or downsizing. For example, enabling the business to setup
project offices or temporary points of sale very rapidly without long delays or IT notification
periods.
Bring Your Own Device: Empower employees to choose their own devices to improve
productivity, collaboration and mobility.
Collaboration: With an increase in both globalization and mobility, team members are often
dispersed across multiple physical locations. Powerful collaboration capabilities are required
to ensure high levels of productivity, efficiency and quality.
Work From Anywhere: The business needs to support home workers in order to attract and
retain top talent, and / or travelling employees.
IT Decision Makers Better Desktop Management: Simplify the management of desktop infrastructure. IT is not
as proactive as they would like and spend too much time ‘fighting fires’.
Increase Security: Data theft or the loss of devices which contain sensitive data (e.g.
laptops or tablets) is a big risk and preventive measures are a top priority.
Extend Desktop Hardware Lifecycle: Replacing workstations every three to five years in
order to keep up with the requirements of the operating system or the applications has been
very costly.

Table 1: Sample Business Drivers

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The prioritization process should be completed in collaboration with the project team, business managers
and IT managers so that all views are considered.
Early on, organizations often need to estimate the hardware required to support the new solution. Citrix
Project Accelerator provides a fast and accurate way to estimate hardware and storage requirements.

Data Capture
The Data Capture process collects key information on users, devices, applications and infrastructure that
is required during subsequent phases of the project, including User Segmentation, Application
Assessment, Project Roadmap and Design.

Strategies
There are three main techniques that can be used to complete the data capture:
Manual
For small organizations, it is possible to capture user and application data by visiting each desktop
in person or by connecting remotely. Performance counters can be used to acquire raw user data
while the “Add / Remove Programs” applet in Windows XP or the “Program & Features” applet in
Windows 7 can both be used to provide a list of installed applications as well as information on how
often they are accessed.
Most medium and large-sized organizations use an Enterprise Software Deployment (ESD) tool
such as Microsoft System Center Configuration Manager (SCCM). Since the ESD solution is
typically the sole method of deploying application packages to workstations, the project team can
query the ESD configuration to identify which applications are assigned to which desktops.
However, most ESD solutions do not provide details on application performance requirements,
application usage metrics or user installed applications. In addition, significant effort is required to
extrapolate, analyze and document application and desktop information from the ESD tool.
The problem with the manual approach is that it is difficult to gain a good understanding of each
user and application’s performance requirements over time. In addition, the manual approach is
very time intensive per desktop making it inappropriate for medium and large-sized organizations.
It can also be difficult to query application requirements of mobile users who may spend extended
periods of time away from the office.
Survey
A questionnaire can be created and distributed to each business manager to identify user and
application requirements within their departments. Survey questions may also be answered in a
face to face meeting or phone call. Surveys are far less time consuming for the project team than
the manual approach because the focus is now upon the department managers to identify the
applications necessary for their employees to complete their jobs. However, it is unlikely that every
manager within the organization will complete the questionnaire and a completion ratio of 70%
should be considered normal. The results from a survey are typically less accurate than the
manual or automated approach. Although less time consuming than the manual approach,
considerable effort is still required to extrapolate, analyze and document the results from the
returned questionnaires.
Automated
There are a variety of automated inventory tools available that allow for a wide range of information
to be collected, including applications installed, access frequency, and performance requirements.
This data is uploaded to a central database so that reports can be generated across the entire user
and desktop estate. To help reduce the cost and complexity of desktop virtualization projects,
Citrix has partnered with Lakeside Software to provide Project Accelerator users with a free 60-day
license of Lakeside FastTrack. FastTrack is a sophisticated inventory tool that has been developed
specifically based on Citrix methodologies, terminology and best practices. An automated
inventory tool is a great solution for medium and large-sized organizations, however the centralized
infrastructure and agent deployment effort is unlikely to be appropriate for very small organizations

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due to the time required when compared to the manual method. In addition, some organizations
may not allow inventory agents to be installed across the desktop estate or may not have rights to
install the agent on user-owned desktops.
The advantages and disadvantages of each approach are summarized in the following table:

Approach Data for all Results Returned Admin Time per User Involvement
Characteristics Desktop
Manual No ~80% Long Likely
Survey Yes ~70% Medium Yes
Automated No ~100% Short No

Table 2: Comparison of Data Capture Strategies

Although the automated method is accurate, fast and does not inconvenience employees, there are
a number of business characteristics that automated tools cannot identify, for example, what is the
criticality of the user, have the applications been packaged, what is the licensing model and how
frequently is the application updated? Therefore, the recommended approach is to use the
automated method to identify technical characteristics and a survey to identify the business
characteristics.
Recommendations
Don’t forget to follow these top recommendations from Citrix Consulting based on years of
experience:

Citrix Consulting Tips for Success

1. Representative Users: If you don’t have enough time, resources, or licenses to inventory
every desktop in your organization, make sure that you pick a representative subset of
users. For example, deploying an agent on every desktop in the HR department but
missing out the sales and finance departments will impact your results. Take time to ensure
that you select a representative subset of users from every department and role within the
organization. And remember, not all users within the same department are the same.

2. Check the Data: When using an automated inventory tool, regularly check that the data
has been successfully uploaded to the central database. There have been cases reported
where insufficient space has been allocated to the central database resulting in several
weeks of agent data being lost causing the project to be delayed.

3. Monitoring Period: It is extremely important that the automated inventory tool monitors the
desktops over a sufficient period of time. At the very least, monitor the desktops for a
minimum of one month; ideally monitor usage over periods of peak activity such as quarter
end so that you have a good idea of average and peak application performance
requirements. There may be situations where users only need access to a specific
application during quarter end and unless you are running the automated inventory tool at
this time you will not be aware of its usage.

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User Data Capture
Key results from the user data gathering exercise should be documented in the User Assessment
worksheet within the Citrix Virtual Desktop Handbook - Assess Workbook:
Business Characteristics
Business characteristics must be gathered manually from the business managers and cannot be
determined using automated data capture tools.

 Identification:

o Username: Provide a unique identifier for the user being assessed.

o Department: Identify the department that the user belongs to, for example, HR,
Finance or Sales.

o Role: Capture the primary job role of the user, for example developer, accountant or
manager.

o Business Manager: Provide the name and contact details of the user’s business
manager so that you can follow up with additional questions.

o Assigned User Group: Do not complete. This field will be completed during the User
Segmentation.

 Business:

o Primary Data Center: Each user will have a primary data center assigned that will be
used to host their virtual desktop, data, and application servers. Identify the data
center that the user should be assigned to rather than the data center they are
currently using. Users will be grouped based on their primary data center so that a
unique architectural design can be created for each one.

o Mobility: Mobility requirements are used to help determine the appropriate FlexCast
model for each user group. For example, if a user group sometimes connects
remotely, this eliminates the Streamed VHD option, which requires a high-speed local
network. There are four classifications available:

Mobility Requirement
Local Always uses the same physical desktop on an internal, high-speed, secured
network.
Roaming Local Connects from different locations on an internal, high-speed, secured
network.
Roaming Sometimes connects from external variable-speed, unsecure networks.
Offline Sometimes needs desktop access while disconnected from any network.

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o Personalization: Personalization requirements are used to help determine the
appropriate FlexCast model for each user group. For example, if a user group
requires complete personalization, a Hosted VDI desktop with Personal vDisk will be
recommended as the optimal solution. There are three classifications available:

Personalization Requirement
None User cannot modify any user or application settings (e.g. kiosk).
Basic User can modify user-level settings within desktops and apps.
Complete User can make any change, including installing applications.

o Security: Security requirements are used to help determine the appropriate FlexCast
model and policies for each user group. For example, if a user group requires high
security, a Hosted-Shared Desktop, Pooled Desktop or On-Demand Apps FlexCast
model will be recommended as the optimal solution. There are three classifications
available:

Security Level Multi-User Data Can Leave Refresh Desktop MAC / IP
Operating System Data Center After Reboot Address Auditing

Low Yes Yes No No
Medium Yes No No No
High No No Yes Yes

o Criticality: Criticality will be used to determine the level of high-availability, load
balancing and fault tolerance measures required. There are three classifications
available:

Criticality Requirement
Low Desktops can be unavailable for one day or more.
Medium Desktops must not be down for more than four hours.
High Backup desktops must always be available in case the primary fails

Technical Characteristics
o Workload: Collecting user performance requirements will allow the desktop
virtualization infrastructure to be sized appropriately and an appropriate FlexCast
model to be selected. For example, if a user group requires OpenGL graphics, a
Hosted Shared desktop will not be recommended because OpenGL is not optimized
on a Hosted Shared desktop. There are four classifications available:

User Type Characteristics Graphics
Light 1-2 office productivity apps or kiosk DirectX or None
Normal 2-10 office productivity apps with light multimedia use DirectX or None
Heavy Multimedia, data processing or application development DirectX or None
OpenGL OpenGL graphics requirements OpenGL

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Note: Performance thresholds are not identified based on processor, memory or disk
utilization because these characteristics will change dramatically following the
application rationalization and desktop optimization process. In addition, it is likely
that the user’s management tools and operating system will change during the
migration process. Instead, workload is gauged based on the number and type of
applications the user runs.

 User Environment: The user environment is a vital but often overlooked aspect of desktop
virtualization projects. These data points will be required during the design in order to plan
user migration and to schedule preparation work. For example reducing the size of the
profiles and home drives before they are moved.
o User Profile: The user profile holds all user settings related to the look and feel of
Windows and the applications as well as certain application configurations, (e.g. mail
signatures) or application data (e.g. favorites). The following information should be
collected for each user’s profile:
 Profile Type: There are five classifications available for “Profile Type” in the
rd
User Assessment Worksheet: Local, Roaming, Mandatory, 3 Party or
Unknown.
 Profile Version: There are two classifications available for “Profile Version” in
the User Assessment Worksheet: Type 1 (Windows XP) or Type 2 (Windows
Vista / 7).
 Profile Location: Name of the file server used to store the user’s home drive.
 Size (MB): Size of the user’s profile.
o Home Drive: The home drive is typically used to store user and application data. The
following information should be collected for each user’s home drive:
 Home Drive Location: Name of the file server used to store the user’s home
drive.
 Size (MB): Size of the user’s home drive (excluding profile).
 Client Hardware: Client hardware details are captured to decide whether devices should be
reused, rebuilt or replaced. For example, Hosted VDI and Hosted Shared users will not
require a high-performance device. The following information should be collected for each
user’s client device:
o Number of CPUs/Cores
o CPU Speed (GHz)
o Memory (GB)
o Disk Size (GB)
o Operating System
o Age of the System (years)
o Peripherals

Note: Although the Application Assessment will identify the peripherals required by each
application there may be some peripherals that are used directly by the operating system, for
example smartcard readers. The connectivity interface required should be identified because
it may be necessary to create a policy that maps the required interface from the endpoint
device to the virtual desktop.

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 Local Resource Mappings: For reasons of security, resource mappings such as clipboard
and client drives are typically disabled unless there is a specific reason to enable them.
Therefore, the user assessment should identify all resource mappings required so that
appropriate policies can be created during the design. The majority of mappings will be
controlled at the user group or departmental level, however, there may be specific
requirements to restrict or enable mappings for certain users or user groups. The following
information should be collected for each user:
o Local Drives
o Printing
o Clipboard
o Audio
o COM Port
o USB
o LPT

Application Data Capture
Key results from the application data gathering exercise should be documented in the Application
Assessment worksheet within the Citrix Virtual Desktop Handbook - Assess Workbook.

 Identification:

o Application Name & Version: Multiple versions of the same application are likely to
be in use within the organization. Create a new row in the table for each version of
the application.

o Application Owner: If known, provide the name and contact details of the application
owner so that you can follow up with additional questions. If there is no application
owner assigned or you do not know the application owner, enter “Unknown.”

o Status: Identifies whether the application is being considered for deployment to the
new virtual desktop solution. For now, enter a value of “Active” for each application
identified during the inventory.

Technical Characteristics
 Assignment:

o Number of Users: Provide the total number of users that have access to the
application.

o Departments: Document which departments require access to the application.

o User Groups: Access to an application may be restricted to specific user groups. For
example, access to the Citrix administration tools may be limited to the Citrix team
within the IT department.

o Individual Users: Some applications may be restricted to a small number of users
due to licensing or security restrictions. For example, access to a CAD application
may be restricted to a small number of employees within the Design Team.

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 Workload: Collecting application workload requirements will allow the virtualization
infrastructure to be sized and an appropriate application delivery model to be selected. For
example, resource intensive applications will not be delivered via a Hosted Shared Desktop
because there is limited control over how the resources are shared between users. There are
three classifications available for “Workload” in the User Assessment Worksheet:

Workload Requirement
Resource If the application uses more than 1200MHz+ of available processor resources (50% of
Intensive a 2.4GHz CPU) or 1GB+ of RAM then it should be classified as “Resource Intensive”.
OpenGL If the application is graphically intensive, certain delivery models may be more
appropriate than others. For example, XenApp supports HDX 3D which offers GPU
acceleration for DirectX only while XenDesktop supports HDX 3D Pro which offers
GPU acceleration for both DirectX and OpenGL. Therefore, Open GL based
applications, should be classified as “OpenGL”.
None The application is not resource intensive and does not require OpenGL graphics.

 Business: Do not complete. This section of the worksheet will be completed during the
Application Assessment, once the application list has been completed.

 Compatibility: Do not complete. This section of the worksheet will be completed during the
Application Assessment, once the application list has been completed.

To save time and effort, the remaining items in the Application Assessment worksheet will be
completed during the Application Assessment once the rationalization process has been completed.

Capabilities Assessment
The information captured during the Capabilities Assessment will be used to achieve the following
objectives:
1. Identify Risks: Like traditional desktops, desktop virtualization is dependent on a wide range
of supporting technologies, including storage, networking, directory services and applications.
In many cases, issues reported with virtual desktops are a symptom rather than a cause. For
example, slow performance and disconnected sessions are more often caused by periods of
high-latency than a desktop specific issue. Therefore, a desktop virtualization project is an
excellent opportunity to review an organization’s existing infrastructure to ensure that it
provides a good solid foundation upon which the VDI environment can be built. Any risks
identified should be reported to the project manager so that they can be addressed
appropriately.
2. Create Roadmap: The Capabilities Assessment provides the project team with a detailed
understanding of the existing environment so that they can estimate implementation time for
each user group and prioritize the implementation order.
3. Virtual Desktop Design: Provide the project team with detailed information on the current
state of the environment so that they can successfully integrate the new virtual desktop
solution. The Capabilities Assessment should also determine whether existing infrastructure
components can be leveraged or whether new infrastructure needs to be purchased, for
example shared storage and virtualization technologies.
Key results from the capabilities gathering exercise should be documented in the Citrix Desktop
Virtualization Handbook – Capabilities Assessment template. A list of questions has been provided
per infrastructure technology to highlight key information that needs to be collected. These questions
are based on the experiences of Citrix Consulting across numerous desktop virtualization projects and
should be answered by the appropriate technology architect for each section. Not all sections need to
be completed, for example if the organization does not already have a Citrix XenApp or XenDesktop
environment this section can be left blank. The length of the capabilities assessment will vary based
on the size and complexity of the environment but typically takes about three days to complete.

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Recommendations
Performing a capabilities review helps set the foundation for the design by identifying experiences,
technologies and platforms to pursue. The review should first focus on whether the following areas
have already been implemented and if so, what is the current satisfaction – Access, Desktops,
Active Directory, XenApp/XenDesktop, Database, Virtualization, Storage, Network and Operations.
Don’t forget to follow these top capabilities assessment recommendations from Citrix Consulting,
which are based on years of experience:


1. Discussions: Meet with the architects rather than sending them a questionnaire so that
additional questions can be raised, diagrams drawn and detailed explanations provided.

2. Schedule Meetings: It is advisable to schedule meetings with the architects well in
advance to ensure availability. Provide each architect with a copy of the questions that
you plan to ask them so that they can prepare appropriately. Also, when scheduling the
meetings request any relevant documentation for background reading as this may prompt
additional questions and discussions.

3. Documentation: Use this document to capture your discussions with the architects. The
document can then be circulated amongst the project team to ensure that everybody has
the same information.

4. Future Initiatives: Ask the architects whether they are planning any future initiatives, for
example upgrading to a new product version, or adjusting the architecture. This will
ensure that the project team is aware of all upcoming changes.

5. Identify Risks: It is important that all risks are identified as early as possible so that they
can be tracked and appropriate action taken. Risks should be graded in severity and if
possible remediation plans should be created stating an estimated time-frame and cost.

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User Segmentation
Once the data capture is complete, you’re ready to start dividing up the users into different groups based
on a common set of requirements. This allows a FlexCast model to be assigned to each user group
without compromising on performance or functionality.

User Groups
Users are often classified as “task workers”, “branch office workers”, “mobile workers” and the like.
Unfortunately, this classification is too broad to offer meaningful segmentation because many real
users can simultaneously be described as task workers, mobile workers, and branch office workers.
Instead, group users together that have the same requirements for:
1. Primary Data Center
2. Workload
3. Mobility
4. Personalization
5. Security
6. Criticality

Utility Company: A large utility company collected data on every user in their organization. During
the user segmentation process it was realized that the organization’s existing role definitions were
sufficiently well defined that all the users within a role shared the same requirements. This allowed a
significant amount of time to be saved by reviewing a select number of users per group.
Government: A government organization discovered that there was significant deviation between
user requirements within each role, particularly around security and criticality. As such, each user
needed to be carefully reviewed to ensure that they were grouped appropriately.
The fastest and easiest way to identify your user groups within the User Assessment workbook is to
filter the results based on these key requirements. Once you have identified the users within one
group, transfer the relevant information to the User Segmentation worksheet within the Citrix Virtual
Desktop Handbook - Assess Workbook.

FlexCast
As with physical desktops, it is not possible to meet every user requirement with a single virtual
desktop type. Different types of user need different types of desktop. Some users may require
simplicity and standardization, while others may require high levels of performance and
personalization. Implementing a single desktop virtualization model across an entire organization will
inevitably lead to user frustration and reduced productivity.
Citrix FlexCast offers a complete set of application and desktop virtualization technologies that have
been combined into a single integrated solution. Because each FlexCast model has different
advantages and disadvantages, it is important that the right model is chosen for each user group
within the organization.
This chapter will identify the different FlexCast models available and provide guidance on how to
select the most appropriate one for each user group.

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FlexCast Model Comparison
There are five FlexCast models available, the advantages and disadvantages of each model are
described below:
 Hosted Shared: With the Hosted Shared Desktop model, multiple user desktops are hosted
on a single server-based operating system. The Hosted Shared Desktop model provides a
low-cost, high density solution, however applications must be compatible with a multi-user
server based operating system. In addition, because multiple users are sharing a single
operating system, users are restricted from performing actions which may negatively affect
other users, for example installing applications, changing system settings and restarting the
operating system. There is also the potential that a single user could consume an unfair
share of resources which may negatively affect other users. The Hosted Shared FlexCast
model is provided by Citrix XenApp in combination with Microsoft Remote Desktop Services
(RDS).
 Hosted VDI: The Hosted VDI FlexCast model provides each user with a desktop operating
system. Hosted VDI desktops are less scalable than Hosted Shared desktops because each
user requires their own operating system. However, Hosted VDI desktops remove the
requirement that applications must be multi-user aware and support server based operating
systems. In addition, the Hosted VDI model provides administrators with a granular level of
control over the number of virtual processors and memory assigned to each desktop. The
Hosted VDI model is provided by Citrix XenDesktop, and offers the following sub-categories:
o Pooled-Random / Streamed: Desktops are based on a single master image and
provisioned using Citrix Machine Creation Services or Citrix Provisioning Services. Users
are dynamically connected to one of the desktops in the pool each time they logon.
Changes to the desktop image are lost upon reboot.
o Pooled-Static: Desktops are based on a single master image and provisioned using
Citrix Machine Creation Services or Citrix Provisioning Services. Users are allocated a
virtual desktop on first access. Once assigned, users will always be connected to the
same virtual desktop. Changes to the desktop image are lost upon reboot. If high
availability is required (medium-criticality), the personal vDisk must be stored on shared
storage.
o Pooled / Streamed with Personal vDisk: Desktops are based on a single master image
and provisioned using Citrix Machine Creation Services or Provisioning Services. Users
are allocated a virtual desktop on first access. Once assigned, users will always be
connected to the same virtual desktop. Changes to the desktop are stored in a personal
vDisk and retained between reboots. Desktops with a personal vDisk cannot be shared
between multiple users; each user requires their own desktop. If high availability is
required (medium-criticality), the personal vDisk must be stored on shared storage.
o Dedicated: Desktops are based on a single master image and provisioned using Citrix
Machine Creation Services. Users are allocated a virtual desktop on first access. Once
assigned, users will always be connected to the same virtual desktop. Any changes
made by the user persist for the life of the virtual desktop, even across reboots. Once a
rd
dedicated desktop has been created it must be maintained manually or via 3 party
desktop management tools. Changes to the master image are not reflected on existing
dedicated desktops.
o Existing: Virtual desktops which have not been created using Citrix Machine Creation
Services or Citrix Provisioning Services. For example, a manual build, from template,
rd rd
cloned or using 3 party tools. These desktops must be managed manually or with 3
party desktop management tools.

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o Physical / Remote PC: Physical Desktops that have already been deployed, including
Blade PCs and user workstations (Remote PC). These desktops must be managed
rd
manually or with 3 party desktop management tools. Physical desktops with a GPU
support HDX 3D pro, however Remote PC uses the standard ICA thinwire protocol and
does not allow offloading to the GPU to render video files or 3D apps.
 Streamed VHD: Desktops are based on a single master image and provisioned using
Provisioning Services. The Streamed VHD FlexCast model allows Windows 7, Vista, or XP
desktops to be run locally on the user’s desktop computer. Streamed VHD is a great solution
for high-end workstations because it allows them to leverage local processing power.
Streamed VHD requires a LAN connection to be in place between the desktop and the
Provisioning Servers and changes to the desktops are lost upon reboot.
 Local VM: Windows 8, Windows 7, Vista, or XP desktops running locally within a hypervisor
on the user’s laptop. The virtual desktop image is completely delivered to the hypervisor to
allow for offline connectivity. Citrix XenClient is used to provide the Hosted Shared FlexCast
model.
 On-Demand Apps: The On-Demand Apps FlexCast model does not provide users with a
virtual desktop; instead Windows applications are centralized in the data center, and instantly
delivered via a high-speed protocol (requires connection) or streamed (offline support) via
Citrix Application Streaming or Microsoft App-V.
The following table provides a summary of the different FlexCast models available:

FlexCast Model User Image Delivery Virtual / Physical Access Desktop to
Installed Technology User Ratio
Apps
Hosted Shared No Installed or PVS Physical / Virtual HDX 1 : Many
VDI: Pooled-Random No MCS Virtual HDX 1 : Many
VDI: Pooled-Static No MCS Virtual HDX 1:1
VDI: Pooled with PvD Yes MCS Virtual HDX 1:1
VDI: Dedicated Yes MCS Virtual HDX 1:1
VDI: Existing Yes Installed Virtual HDX 1:1
VDI: Physical / Remote PC Yes Installed Physical HDX 1:1
VDI: Streamed No PVS Physical / Virtual HDX 1 : Many
VDI: Streamed with PvD Yes PVS Physical / Virtual HDX/Local 1:1
Streamed VHD No PVS Physical HDX 1:1
Local VM Yes XC Virtual (XenClient) HDX 1:1
On Demand Apps No Installed or PVS Physical / Virtual Local 1 : Many

Table 3: FlexCast Model Comparison

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FlexCast Model Selection

There are key technical differences between XenApp and XenDesktop. Both products provide the
user with an excellent user experience based on HDX. However, due to their underlying
architecture, many HDX features are slightly different, as shown in the following table:

Criteria XenDesktop 5.6 XenApp 6.5
HDX Broadcast No major differences
HDX MediaStream  24 fps (configurable to 30)  12 fps (configurable to 30)
(server rendered)  Adaptive display
 Low latency audio path
HDX MediaStream No major differences
(Flash redirection &
Windows Media
Redirection)
HDX Plug-n-Play  Generic USB support on the LAN in  General support for Windows
addition to all optimized virtual portable USB devices (standard
channels for device level keyboards, mice, printers,
redirection. smartcards, etc.).
 On a LAN environment, should be  Optimized virtual channels for
able to support most USB devices. device level redirection rather than
USB port level redirection,
potentially limiting availability for
certain USB devices.
HDX WAN No major differences
HDX Rich Graphics  HDX 3D Pro (not supported on  DirectX acceleration (shared GPU)
Remote PC) for deep GPU-based
compression and OpenGL/DirectX
acceleration (one GPU per user)
 Adaptive Display
 Microsoft RemoteFX support
 Aero Redirection
HDX 3D Pro  GPU acceleration of DirectX and  GPU acceleration of DirectX only
OpenGL  Each GPU can be shared by
 One user per GPU multiple users
 Deep-level compression  Applications must be compatible
 3D SpaceMouse support with RDS
HDX Smart Access No major differences
HDX RealTime  Low latency audio path  Softphone compatibility somewhat
 UDP/RTP support for tolerance to limited due to use of Windows
network congestion and packet loss Remote Desktop Services (formerly
 DSCP and WMM packet tagging Terminal Services)
HDX Adaptive No major differences
Orchestration

Table 4: XenApp and XenDesktop Feature Comparison

Note: An overview of HDX technologies can be found on the Citrix HDX site.

Each user group in the User Segmentation worksheet should be compared against the following
table to determine which FlexCast Model should be assigned. Ensure that you update the
FlexCast value for each user group in the worksheet.

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Segmentation Hosted VDI: VDI: VDI: VDI: VDI: VDI: VDI: Streamed Local VM On
Characteristic Shared Pooled- Pooled- Pooled / Dedicated Existing Physical Remote VHD Demand
Random / Static Streamed PC Apps
Streamed with PvD

Workload
Light           
Normal           
Heavy           

Open GL           
Mobility
Local           
Roaming Local           
Remote           
Offline           
Personalization
None           
Basic           
Complete           

Security
Low           
Medium           
High           
Criticality
Low           
Medium           
High           
“”: Recommended. “” Viable. ““. Not Recommended. “”: Streamed Apps Only.
Table 5: FlexCast Model Capability Comparison

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Recommendations
Don’t forget to follow these top recommendations from Citrix Consulting based on years of
experience:


1. Review the Capabilities Assessment: There are multiple FlexCast models available that
are an equal match, for example VDI: Pooled Random (Provisioning Services) and VDI:
Streamed (Machine Creation Services). In this situation, refer back to the results from the
Capabilities Assessment. If you already have skills or experience with one model over
another then this is a good reason for selecting it.

2. Lead with Hosted Shared/VDI: As you can see in the FlexCast Capability table above, the
Hosted VDI and Hosted Shared FlexCast models can be used in the majority of situations.
The Streamed VHD and Local VM FlexCast models should only be used on an exception
basis. By reducing the number of FlexCast models required, you will help to reduce
deployment time and simplify management.

3. Perfect Match. It may not be possible to select a FlexCast model which is a perfect match
for your user group, for example you can’t provide users with a desktop that is highly secure
and offers complete personalization at the same time. In these situations, select the
FlexCast model which is the closest match.

4. Criticality. There are only four FlexCast models that meet the needs of a high criticality user
group (backup desktops available) – none of which allow for complete personalization. If a
high-criticality user group also requires the ability to personalize their desktop they could be
provided with a pool of backup desktops (Hosted Shared, pooled, streamed) in addition to
their primary desktop. Although these desktops would not include customizations made to
their primary desktop, they would allow users to access core applications such as mail,
Internet and Microsoft Office.

Application Assessment
At the completion of the user segmentation exercise, users will be divided up into groups based on a
common set of requirements. The next step is to provide users with the applications they need to perform
their jobs. There is a three-step process that will help guide you through the assessment of these
applications:

1. Rationalization: Help to simplify the application assessment by removing redundant applications
from the inventory that was captured during the data gathering chapter.

2. Business Characteristics: Work with application owners to define key application characteristics
that can’t be determined using automated assessment tools or end-user questionnaires.

3. Compatibility: Establish whether the remaining applications are compatible with your preferred
delivery models (typically Windows 7 and Windows 2008 R2 with XenApp) so that an appropriate
choice can be made during the design.

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This chapter will provide guidance on how to complete each step and to document the results in the
Application Assessment worksheet within the Citrix Virtual Desktop Handbook - Assess Workbook.
It is important to remember that this is still the assessment phase of the project and that application
delivery solutions should not be selected until the design phase when all relevant information is available.

Rationalization
The number of applications identified during the inventory is often surprising, even for organizations
that believe they have a high-level of control over applications. To help reduce complexity as well as
overall time required, it’s important to take the time to consolidate the list of applications. Start by
arranging an “Application Assessment” meeting with all relevant application owners.
Note: Consolidated applications should be identified within the Application Inventory Workbook by
selecting “Consolidated” in the Status column. Consolidated applications should not be removed from
the workbook so that the rationalization process can be reviewed within the organization.
The following guidelines will help to ensure that your application list is consolidated appropriately:

 Multiple Versions: Different versions of the same application may have been identified during
the inventory. There are various reasons for this, including an inconsistent patching or
upgrade process, decentralized application management, limited licenses and situations
where users require specific application versions for compatibility with other applications,
macros and document formats. Where possible, work with the application owners to reduce
the number of versions required. The best practice is to standardize on a single version of
each application, typically the latest.

 Business Applications: Applications which are not required by the business should be
removed from the application inventory to reduce resource requirements and to help simplify
the overall project. Non-business related applications are typically found in an application
inventory when users have been provided with the ability to install their own applications and
typically include games, communication clients, screen savers, peripheral software and media
players.

 User Installed Applications: Applications which have been installed by users, rather than the
IT department, should be reviewed to ensure that they are appropriate and have a business
purpose. Ensure that the application vendor is trusted, appropriate licenses have been
purchased, and that there is a legitimate reason for the organization to support these
applications.

 Legacy Applications: The inventory may identify legacy applications that have since been
retired or that are no longer required within the business. These applications may not have
been removed from the desktops because there is no established process to do so or
because there are always more high-priority activities to complete. These applications should
be consolidated during the rationalization stage of the application assessment.

 Management Applications: The antivirus, application delivery, monitoring, inventory,
maintenance and backup applications will be completely re-designed across the organization
during the desktop virtualization project. These applications should also be consolidated
during this stage.

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Government: A government organization identified that there were 2,660 applications installed
across their desktop estate. Most of which were installed by users with local administrative rights. By
following the application rationalization recommendations above, it was possible to reduce the
number of applications required to 160.

Business Characteristics
Once the application list has been rationalized, time should be taken to identify the business
characteristics that cannot be determined using automated data capture tools. The characteristics of
each application should be documented in the Application Assessment worksheet within the Citrix
Virtual Desktop Handbook - Assess Workbook.

 Update Frequency: The time and effort required to update an application will vary according
to the delivery model chosen. For example, it is faster to update an application installed into a
provisioned Hosted Shared desktop image than a VDI: Existing one. Therefore, each
application should be classified based on its update frequency so that an appropriate delivery
model can be selected during the design. There are four classifications available for “Update
Frequency” in the Application Assessment Workbook:

Update Frequency Requirement
Low One or two updates required per year.
Medium One or two updates required per quarter.
High One or two updates required per month.

 Packaged: Packaged applications are installed in an automated fashion without intervention.
Application packaging reduces deployment time and ensures that applications are installed
consistently across the environment. If the design team requires additional packaging to be
completed, sufficient time should be incorporated into the Deploy phase to complete this
activity.

 Criticality: Application criticality will be considered during the design phase to ensure that the
delivery model selected incorporates a sufficient level of redundancy to meet business needs.
However, there may be situations where different user groups or departments require a
different level of criticality to others. For example, the criticality of Microsoft Office may be
high for the sales department and low for the helpdesk user group. If so, select the highest
criticality required. There are four classifications available for “Criticality” in the Application
Assessment Workbook: High, Medium, Low or Unknown.

 Technically Challenging: An application should be classified as technically challenging if it is
complex to set up, has extensive dependencies on other applications or requires a specialized
configuration, for example an Electronic Medical Records (EMR) application. Technically
challenging applications need to be identified during the application assessment because they
are not generally appropriate for installation in to a base desktop image or delivery by
application streaming. Delivering technically challenging applications as XenApp published
applications will help to reduce the complexity of the base desktop image. There are three
classifications available for “Technically Challenging” in the Application Assessment
Workbook: Yes, No or Unknown.

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 Works Offline: Some user groups may require the ability to work offline. If so, it is important
that the design can determine which applications will work without a network connection and
which ones will not. Applications which require backend infrastructure such as web and
database servers are not typically available offline. There are three classifications available
for “Works Offline” in the Application Assessment Workbook: Yes, No or Unknown.

 Remote Application Servers: For optimal performance, application servers should be hosted
in close proximity to the virtual desktops because this helps to reduce latency and prevent
network capacity from becoming a bottleneck. However, traditional physical desktop
environments sometimes locate application servers in WAN sites so that they are in close
proximity to the desktops. The application assessment should determine whether any of the
application servers are currently hosted outside of the data center so that time is taken during
the design to determine whether it is possible to relocate these servers. There are three
classifications available for “Remote Application Servers” in the Application Assessment
Workbook: Yes, No or Unknown.

 Peripheral Connectivity. If applications require connectivity with peripheral devices, the
application assessment should determine which connectivity interface is required because it
may be necessary to create a policy that maps the required interface from the endpoint device
to the appropriate application. There are five classifications available for “Peripheral
Connectivity” in the Application Assessment Workbook: No, USB, TWAIN, LPT or COM.

 Restricted Access: Application access may need to be restricted due to insufficient licenses /
resources and to protect sensitive data / tools. For example, applications with a limited
number of licenses should not be installed in to a base image that is shared with unlicensed
users. The Application Assessment Workbook allows four options for “Restricted Access” to
be selected:

Restricted Access Requirement
No There are no security restrictions for the application and it can be accessed by any
user within the organization.
User Group The application may be installed on a multi-user operating system but only a
specific group of users should be provided with an icon.
Virtual Machine Application should only be installed on a virtual machine that is accessible by
authorized users.

Compatibility
Desktop virtualization typically requires significant changes to be made to an organization’s application
delivery strategy. For example, many organizations will take the opportunity to upgrade their desktop
operating system and to simplify management by reducing the number of applications installed into the
base image using techniques such as application streaming and seamless applications. These are
significant changes that require comprehensive compatibility testing so that an appropriate delivery
model can be selected for each application during the design. Important compatibility requirements
that may need to be verified include:

 Desktop Operating System: If the application is to be streamed or installed into a Hosted
VDI Desktop, the application must be compatible with the preferred desktop operating system.

Page 27

 Server Operating System: Some applications may be more appropriate for delivery via a
Hosted Shared Desktop or published application. In these situations, the compatibility of the
application must be verified against the chosen server operating system, for example
Microsoft Windows Server 2008 R2.

 Application Architecture: It is important to understand whether the application includes 16-
bit, 32-bit or 64-bit code so that an appropriate operating system can be selected. 16-bit code
cannot be executed on a 64-bit operating system such as Microsoft Windows Server 2008 R2,
Microsoft Windows XP x64, or Microsoft Windows 7 x64.

 Interoperability: Some applications may experience complications if they coexist on the
same operating system. Possible causes include shared registry hives, DLLs or INI files as
well as incompatible dependencies. Application interoperability issues should be identified so
that appropriate remediation steps can be taken or an alternative delivery model selected.

 Application Streaming: The use of application streaming helps to simplify image
management by reducing the number of applications installed into the base image. However,
not all applications are suitable for streaming because they may install device drivers, use
COM+ or form part of the operating system. For an up-to-date list of limitations, please refer
to the documentation of your preferred application streaming solution vendor.

There are three main techniques that can be used to perform the application compatibility testing
component of the application assessment:

 Manual: With manual application compatibility testing, each application is installed into the
target environment and manually tested. Manual testing is very time consuming because it
requires a full application test per delivery model. In addition, it is difficult to test every aspect
of the application and almost impossible to identify every application interoperability conflict.
As a result, most of the compatibility issues are identified by production users rather than the
testing process.

 Pre-Verified Applications: Most application vendors will supply detailed information on which
operating systems and delivery models their application supports. Please refer to the
application vendor’s documentation for more information. In addition, the Citrix Community
Verified site maintains a list of applications which Citrix customers and partners have verified
as being compatible with XenApp, XenDesktop and application streaming. Microsoft also
maintains a spreadsheet of applications which have been verified as being compatible with
Microsoft Windows 7 by the software vendor or by the Windows 7 Logo Program. Please
refer to the Microsoft Windows 7 Application Compatibility List for IT Professionals for more
information.

The problem with pre-verified applications is that they are unlikely to provide compatibility
information for every application identified during the inventory and there won’t be any
information available on applications which have been fully or partially developed in-house. At
best, there will be limited information available on application interoperability issues.

 Automated Tools: Citrix AppDNA allows applications to be quickly and accurately analyzed
for compatibility across all relevant operating systems and delivery models including Microsoft
Windows XP, Microsoft Windows 7, Citrix XenApp, Microsoft App-V and Citrix Application
Streaming. Applications are imported into AppDNA where they are analyzed against
thousands of application compatibility rules and checked for interoperability issues. When

Page 28

compatibility issues are identified, AppDNA provides an explanation of the issue, possible
remediation actions and an estimate of the time required to resolve the issue.

The advantages and disadvantages of each approach are summarized in the following table:

Approach Time Required Cost Complexity Interoperability Accuracy
Manual High Low High Limited Low
Pre-Verified Medium Low Medium Limited Medium
Automated Tool Low Medium Low Yes High

Table 6: Application Compatibility Testing Approaches

Regardless of the approach used, the compatibility testing results should be captured in the
“Compatibility” section of the Application Assessment Workbook so that they can be analyzed during
the design phase:

 Pre-Requisites: Many applications will depend on certain pre-requisites to function correctly,
for example, the Java Runtime Environment, .Net Framework or a database driver. All
essential pre-requisites should be captured during the application assessment so that an
appropriate image design can be created.

 Dependent Apps: Applications may need to interact with each other to provide the users with
a seamless experience. For example, applications that present information in a PDF format
require a suitable PDF viewer to be available. Capturing application dependencies will help to
ensure that an appropriate image design can be created.

 16-bit Code: The application assessment should determine whether the applications include
any 16-bit code because they cannot be supported on a 64-bit operating system. There are
three classifications available for “16-bit Code” in the Application Assessment Workbook: Yes,
No or Unknown.

 Windows XP: Specify whether the application passed compatibility testing for Microsoft
Windows XP. There are six classifications available for “Windows XP” in the Application
Assessment Workbook: Yes – No Remediation, Yes – Low Remediation, Yes – Medium
Remediation, Yes – High Remediation, No or Unknown.

 Windows 7: Specify whether the application passed compatibility testing for Microsoft
Windows 7. There are six classifications available for “Windows 7” in the Application
Assessment Workbook: Yes – No Remediation, Yes – Low Remediation, Yes – Medium
Remediation, Yes – High Remediation, No or Unknown.

 XenApp 6.5: Specify whether the application passed compatibility testing for Citrix XenApp
6.5. There are six classifications available for “XenApp 6.5” in the Application Assessment
Workbook: Yes – No Remediation, Yes – Low Remediation, Yes – Medium Remediation, Yes
– High Remediation, No or Unknown.

 Application Streaming: Specify whether the application passed compatibility testing for
application streaming. There are five classifications available for “Application Streaming” in
the Application Assessment Workbook: Yes, No, Citrix Streaming Only, App-V Only or
Unknown.

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Recommendations
The application assessment portion can be a frightening process due to the sheer number of things to
take into account. However, most applications within an organization’s complete inventory are fairly
standard. The key to doing an application assessment is to

 Focus on the inventory first

 Reduce the inventory as much as possible

 Classify remaining applications into defined categories

 Verify compatibility only on the applications and delivery methods deemed important

Don’t forget to follow these top application assessment recommendations from Citrix Consulting, which
are based on years of experience:


1. Remember the Plugins: Plugins are available for various applications, including Microsoft
Internet Explorer, Microsoft Word and Microsoft Outlook. For example Citrix ShareFile and e-
mail archiving solutions are frequently implemented as plugins. To prevent critical functionality
being omitted, plugins should be treated as applications during the application assessment.

2. Application Dependencies: It is imperative that you understand all of the interactions
between your applications. For example, there may be an application which requires Microsoft
Word and Excel be installed on the same system so that reports can be viewed. When it
comes to the design phase of the project you will need to make sure that these applications
are grouped together appropriately.

3. Application Consolidation: It may be tempting to skip through the application consolidation
phase of the assessment, but time spent reducing the number of applications significantly
reduces complexity and time spent on the assessment and design phases of the project.

4. Compatibility Testing: There may be pressure to drop application compatibility testing due to
limited time, budget and resources. However, this phase of the assessment is critical because
it will significantly reduce application testing time and the number of issues that creep into
production which can cause users and the business to lose confidence in the new
environment.

5. Application Owners: To ensure that you don’t incorrectly categorize applications or remove
an important application from your inventory ensure that you identify and work closely with the
various application owners during the Rationalization, Characteristics and Compatibility Steps.

6. Manual Compatibility Testing: Manual compatibility testing may be chosen in preference to
an automated solution such as AppDNA due to licensing costs. However, manual compatibility
testing has been shown to be error prone, time consuming and more expensive than using an
automated solution.

7. Final Check: Once the consolidated list of applications has been finalized, complete with
characteristics and compatibility information it should be sent to the application owners for
review to ensure that it is correct and no critical applications or information has been omitted.

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Project Management
Roadmap
Most companies don’t have sufficient time or resources to migrate every user group in one go. As
such, it is important that the user groups identified are prioritized so that the business receives the
maximum value from their investment as soon as possible. To achieve this, you need to compare the
business impact and time to value of each group:
 Business Impact: Consider the impact that desktop virtualization will have on each user
group and rank them accordingly. It is important that you double back here, and use the
Business Drivers identified at the start of the project to make sure that you assign an
appropriate ranking. Don’t just assign ratings based on how highly the business values each
user group; instead focus on which user groups offer the most benefit to the company after
virtualization. It’s a subtle but important difference.
 Time to Value: For each user group, estimate how long it will take to implement the chosen
FlexCast model based on the findings from the Capabilities Assessment. For example, you
might find that a company already has a XenApp farm that can be leveraged to support those
user groups that require a Hosted Shared Desktop resulting in a low Time to Value.
Alternatively, the business might have no prior experience with XenClient resulting in a longer
time to value. Compare application sets, user requirements and user numbers when
differentiating between user groups that have been assigned the same FlexCast model.
Note: If there are limited skills available in-house to implement a chosen FlexCast model,
consider hiring external resources so that Time to Value can be reduced for the associated
user groups.
Representing this information in a graph provides an easy way to visualize the results:

Figure 3: User Group Prioritization

When it comes to assigning the implementation order, start from the top left hand corner of the chart
and work your way to the bottom right hand corner. This way you start with some quick wins that offer
a high-level of value to the company.
Once the project roadmap has been created, update the project plan so that it incorporates the
prioritized roadmap.

Utility Company: A large utility company realized that there would be a long Time to Value for user
groups that had been assigned with a Hosted VDI FlexCast mode, because they had no prior
experience or training with this technology. To address this concern, the utility company engaged
with Citrix Consulting who provided Consultants with previous experience of successfully deploying
XenDesktop.

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Project Team
Desktop virtualization is a fundamental change that requires close collaboration between various
business and technical teams in order to be successful. For example, the virtualization and desktop
teams need to work together to ensure that the virtual desktop image meets user needs while also
being optimized for the data center. Failure to build a cohesive project team that consists of the right
roles and skillsets can negatively impact performance, availability, user experience and supportability
while also increasing costs and risk.
The following tables identify the business and technical roles required during an enterprise virtual
desktop deployment. Although the list may seem quite large, many of these roles are only required for
a short time and multiple roles may be performed by a single person. The project manager and Citrix
Architect are considered to be full time roles with other team members being brought in only when
required. The Project Manager role is key to ensuring that the right people are involved in the project
at the right time.
Business Roles
Role Description Example Responsibilities
Project Sponsor The Project Sponsor is a senior Pre-project
company executive who recognizes  Promote desktop virtualization within
the benefits that desktop
business
virtualization will bring to the
business. The Project Sponsor  Identify members of the steering committee
role is often performed by the Chief Secure funding
Technology Officer (CTO).
 Assess
 Identify and prioritize key business drivers

Project Manager The Project Manager directs the All Steps
project team and is responsible for  Define key project milestones
ensuring that project objectives are
completed on time and within  Create and update project plan
budget.  Track progress against plan
 Track expenditure against budget
 Maintain issue and risk register
 Manage scope changes
 Create weekly project reports
 Brief steering committee on progress
 Organize project workshops and meetings
 Ensure project teams are synchronized
 Ensure pre-requisites are in place
 Creates change control requests

Business Depending on company structure Assess
Manager and size, Business Managers  Assist with application consolidation project
oversee planning and performance
at a department, region or  Provide details on connectivity requirements
company level. A Business of user group, including offline usage
Manager will understand the
 Provide details on risk tolerance of user
requirements necessary for their
employees to be successful. group
 Identify requirements for peripherals
Deploy
 Promote benefits of desktop virtualization
 Assist with coordinating the rollout

Page 32

Business The Business Continuity Manager Assess
Continuity ensures that an organization can  Provide Citrix Architect with detailed
Manager continue to function after a
understanding of the current business
disruptive event such as natural
disaster, crime or human/computer continuity plan
error. Design
 Update business continuity plan to
incorporate the new Citrix infrastructure
Deploy
 Test business continuity plan

Test Manager The Test Manager is responsible Assess
for ensuring that the test and user  Provide Citrix Architect with detailed
acceptance environments match
understanding of current testing
the production environment as
closely as possible. The Test infrastructure and processes
Manager helps to reduce risk by Design
ensuring that changes are fully
 Work with Citrix Architect to design an
tested before being implemented in
production. appropriate testing infrastructure and test
plan for new Citrix environment
Deploy
 Ensure that testing design is implemented
correctly and new Citrix infrastructure is fully
tested before rollout

Application An Application Owner is a subject Assess
Owners matter expert on specific  Assist with application consolidation project
applications deployed within the
business. Application owners are  Identify application licensing limitations
responsible for ensuring that  Provide details on security restrictions
problems with the applications are
resolved and that  Provide details on application dependencies
upgrades/updates are performed  Provide location of backend resources
without issue. Application owners
are also responsible for managing Deploy
support agreements with the  Provide installation pre-requisites and install
application vendors. guide
 Assist Citrix team with installing and testing
applications in VDI environment

Service Desk The Service Desk Manager helps Assess
Manager to improve productivity and end-  Identify common issues with existing
user satisfaction by ensuring that
environment
production issues are logged,
escalated and resolved in a timely  Provide details on support tools currently
manner. The Service Desk used
Manager is also responsible for
Design
reporting on common issues, call
volumes and service desk  Assist Citrix Architect with designing a
performance. delegated administration model
 Participate in operations and support design
workshops
 Work with Training Manager to identify
training requirements
Deploy
 Monitor helpdesk calls for rollout related
issues

Page 33

Citrix Virtual Desktop Handbook

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