Description of design process

Description of
Design Process
CONCEPTS IN ENGINEERING DESIGN
Chapter 3-41

Concept Development
Embodiment design
Detail Design
PRODUCT
3

THE PRODUCT DEVELOPMENT PROCESS.
 Sequence of steps or activities which an enterprise employs to conceive,
design, manufacture & commercialize a product.
4

PRODUCT PLANNING
 It is an activity that considers the portfolio of projects that an
organization might pursue, and
 What subset of these projects the organization would pursue
rigorously over a defined period of time.
9

Why Product Planning?
 It helps determine.. .
 What product development projects to be undertaken?
 What mix of fundamentally new products, platforms and derivative
products to be pursed?
 How do various products relates to each other as portfolio?
 What will be the timing & sequence of the projects?
 Product development team must know its mission before starting the
exercise of development
 Product planning leads to a mission statement for the team.
10

Mission Statement
 What market segments should be considered in designing the product
and developing the features?
 What new technologies (if any) should be incorporated into the new
product?
 What are the manufacturing and service goals and constraints?
 What are the financial targets for the projects?
 What are the budget and time frame for the project?
11

MISSIONSTATEMENT
Product Description
Key Business Goals
Primary Market
Secondary Markets
Assumptions
Stakeholders
12

Product Planning
Helps in Maximizing the effectiveness of its product
development efforts by
 Identifying set of potential projects
 Deciding which projects are most desirable
 Launching each project with a focused mission.
14

Product Plan
 Is dynamic
 Competitive environment
 Changes in technology
 Information management of success stories
 Involves senior management
 Exercised once a year or a few times each year
15

Bad Product Plan leads to
 Not proper coverage of target markets with competitive products.
 Poor timing of introducing products into the market.
 Mismatches between aggregate development capacity and the number of
projects pursued.
 Poor distribution of resources, with some projects overstaffed and others
understaffed.
 Frequent cancellations of poorly planned projects.
 Frequent changes in the goals and destinations of the projects.
16

Who Designs & Develops Products?
Marketing
Design
Manufacturing
17

Challenges of Product Development
 Trade-off
Performance v/s Cost, Efficiency v/s Technology
 Dynamics
Technology , Customer’s change in Preferences, Competitions’ Challenge.
 Details
Cost of 1 g of material can convert into cost of crores of investment.
 Time Pressure
Fast evolving world, small time to decide and without complete
information.
 Economics
Designing, producing & selling takes huge investment & reasonable ROI
(return on investment).
18

Factors for Success
Four key factors that determine the success of a product in the marketplace.
 The quality, performance, and price of the product.
 The cost to manufacture the product over its life cycle.
 The cost of product development.
 The time needed to bring the product to the market.
19

The team that brings the product first to market enjoys an initial price advantage and
subsequent cost advantages from manufacturing efficiencies.
20

Simplified technology development
cycle.
Transferring from one technology growth
curve (A) to another developing technology
(B).
22

Conceptual design
 Conceptual design is the process by which the design is initiated, carried to the
point of creating a number of possible solutions, and narrowed down to a single
best concept. It is sometimes called the feasibility study.
 Conceptual design is the phase that requires the greatest creativity, involves the
most uncertainty, and requires coordination among many functions in the business
organization.
23

The following are the discrete activities that we
consider under conceptual design.
 Identification of customer needs: The goal of this activity is to completely
understand the customers’ needs and to communicate them to the design
team.
 Problem definition: The goal of this activity is to create a statement that
describes what has to be accomplished to satisfy the needs of the customer.
This involves analysis of competitive products, the establishment of target
specifications, and the listing of constraints and trade-offs.
 Gathering information: Engineering design presents special requirements over
engineering research in the need to acquire a broad spectrum of information.
 Conceptualization: Concept generation involves creating a broad set of
concepts that potentially satisfy the problem statement. Team-based creativity
methods, combined with efficient information gathering, are the key activities.
24

 Concept selection: Evaluation of the design concepts, modifying and
evolving into a single preferred concept, are the activities in this step. The
process usually requires several iterations.
 Design review: Before committing funds to move to the next design phase,
a design review will be held. The design review will assure that the design
is physically realizable and that it is economically worthwhile. It will also
look at a detailed product development schedule. This is needed to devise
a strategy to minimize product cycle time and to identify the resources in
people, equipment, and money needed to complete the project.
25

PROBLEM DEFINATION
And
NEED IDENTIFICATION
26

MOTIVATION?
 Identification of a set of customers’ needs
 Product often benefits when they satisfy needs
 Information channel between customers and product developers.
 Use environment.
 Needs ≈ Wants ≈ Customer Attributes ≈ Customer Requirements ≈ Customer
Insights.
27

Targets
 Product is focused on customer needs.
 To identify latent / hidden needs as well as explicit needs.
 Its fact based to justify the specification & concepts there after.
 Creation of archival record of the need activity of the development process.
 No critical product need is missed or non-accounted for.
 Helps in developing common understanding between team.
28

Needs versus Specifications
 Needs independent of product developed.
 Development does not know how and when needs would be fulfilled.
 Needs independent of Concept selected while specifications depends on concept
selected.
 Specifications depends on technical and economic feasibility and product
range of competitors.
 Specifications also depends on customer needs.
29

Stepstoidentifyneeds
Gather Raw Data from Customers
Interpret Raw Data in terms of Needs
Organize the needs into hierarchy,
Primary, Secondary and/or Tertiary
needs
Establish Relative Importance of
Needs
Results Analysis
30

Customer Needs
 Development project starts with specifying
• Particular market opportunity
• Broad constraints, and
• Project objectives
 Mission Statement or Charter or Design Brief
 Mission statement output of Product Planning
 Mission Statement specifies the direction to proceed but does
not specify a precise destination or manner to proceed.
31

User Research
 Defining User Journey Map or Product Touch Points
 Finding Right Customers
 Interviews
 Focus Groups
 Observing Product in Use / Experience it
33

Finding Right Customers
 Identify Users, Buyers, Service Persons & lot more
 Determine Lead Users
- Can articulate their needs
- They might have solutions to address these needs
- Explicit needs of lead users are mostly the Latent need for the
majority market
 Locating Customer
- Recruiting agency
- Sales team
- Social networking
35

Lead Users
 Identifies needs ahead of the
market.
 Needs explicit to them are still
latent for the majority.
 Can articulate their emerging
needs.
 Most often, they invent the
solutions to the problems.
 Helps the designer leapfrog
competition.
36

Interviews
 Conducted at customer’s environment
 Duration one to two hours
37

Focus Groups
 8 – 12 customers; approx. duration two hours
 Moderator governed
 At times video recorded too
 Domain – Market Research
38

Product Observation
 Elicit data on how a customer uses a product.
 Mostly a passive exercise but at times, side-by-side working with a
customer also exercised.
 Do-it-yourself tool – product usage simple and natural.
 Other tools used first on surrogate tasks e.g. surgical tools.
39

Choosing Customers
 Interviews 10 – 50 for single market segment.
 Sequential and terminated as soon as no new data is revealed by the
customer.
 For multiple distinct market segment – 10 or more interviews in each
segment.
 Question to be addressed: Who should be interviewed?
The buyer or the user ???
40

Art of eliciting Customer Needs
 Be receptive and avoid confrontation or defensive posturing
 Mostly verbal
 Prepared interview guide
 Dipstick Interviews with known users
 Go with flow
 Gather all possible information with all possible mean
 Use visual stimuli & props
 Try to find stories
 Go deep under these stories/incidents with follow up questions
43

Art of eliciting Customer Needs
 Avoid preconceived notions being formed about product technology.
 Let the customer demonstrate the product.
 Watch out for surprises and expressions carrying latent needs.
 Non-verbal information – comfort, image or style icon.
 Do observe carefully, facial expression, other movements, especially
“Expressions”.
 Note his/her surrounding in details.
44

Documenting Interactions with customers
 Notes
 Audio Recording
 Video Recording
 Photography
 Debriefing
52

Results
 Raw data in the form of customer statements.
 Data template implemented in spreadsheet Question, Customers’
statement / observation, Interpreted need.
 Clues – humorous remarks, less serious suggestions, frustrations,
nonverbal information, observations and descriptions of the use
environment.
 Thank you Note
53

Interpret Raw Data into Needs
57

58

Needs
 Each observation may be translated into any number of customer needs.
 Multiple analysts are required to translate customer statements into interpreted
needs.
 Some needs technologically not realizable.
 At times, customers give conflicting needs (No attempt to resolve)
 Product Specifications is the output of needs + technical & economic constraints
59

Express the needs in terms of “WHAT” not “HOW”.
60

 Capture the need as specifically as RAW DATA.
 Needs are evolved and expressed at different levels of detail.
 Express the need at the same level of detail as raw data, otherwise loss of
information.
I drop my
phone all the
time
The phone operates normally
after dropped repeatedly by
accident.
The phone is rugged
61

62

63

Organize Needs into Hierarchy
 Primary needs
 Secondary needs
 Tertiary needs
Or Must have, Can have, May have …
65

Organize Needs into Hierarchy
 Procedure for organizing needs into a hierarchy is intuitive.
 Print/write each need on separate card or post it
 Eliminate redundant statement
 Group the cards according to similarity of needs they express
 For each group, choose a Label (group name)
 Create super-groups consisting 2-5 groups
 Review & edit the organized need statements
 Establish relative importance of Needs.
66

Establish Relative Importance of the
Needs
 Numerical weightages assigned.
 Two approaches:
•Consensus of team members based on their experience with the
customers.
•Importance assessment on further customer surveys.
 Trade off – cost and speed v/s accuracy.
 Survey responses characterized by (a) the means, (b) the standard
deviation, or (c) the number of responses in each category.
68

Result and Process Analysis
 Identification of customer needs structured.
 Team must challenge its results to verify that they are consistent with the
knowledge and intuition of the team
 Some points to be taken care are:
1. All important types of customers are interacted
2. The latent needs of the target customers are captured
3. Areas of inquiry to be pursued are identified
4. Identification of customers that may be good participants
5. Any surprise need?
6. All concerned in the organization are associated
7. How the process may be improved in future?
72

Benchmarking
 Benchmarking is a process for measuring a company’s operations against
the best practices of companies both inside and outside of their industry.
 It takes its name from the surveyor’s benchmark or reference point from
which elevations are measured. Benchmarking can be applied to all aspects
of a business. It is a way to learn from other businesses through an
exchange of information.
 Benchmarking operates most effectively on a ‘quid pro quo’ basis as an
exchange of information between companies that are not direct
competitors but can learn from each other’s business operations.
73

Types of Design Information
75

Sources of Information Pertinent to Engineering Design
76

Creative thinking methods
BRAINSTORMING
 The brainstorming process is structured to overcome many of the mental blocks
that curb individual creativity in team members who are left to generate ideas on
their own.
79

Idea Generating Techniques Beyond
Brainstorming
Six Key Questions
Journalism students are taught to ask six simple questions to ensure that they have
covered the entire story. These same questions can be used to help you approach the
problem from different angles.
 Who? Who uses it, wants it, will benefit by it?
 What? What happens if X occurs? What resulted in success? What resulted in
failure?
 When? Can it be speeded up or slowed down? Is sooner better than later?
 Where? Where will X occur? Where else is possible?
 Why? Why is this done? Why is that particular rule, action, solution, problem, failure
involved?
 How? How could it be done, should it be done, prevented, improved, changed,
made?
80

Five Whys
The Five Whys technique is used to get to the root of a problem. It is based on the
premise that it is not enough to just ask why one time. For example:
 Why has the machine stopped? A fuse blew because of fan overload.
 Why was there an overload? There was inadequate lubrication for the bearings.
 Why wasn’t there enough lubrication? The lube pump wasn’t working.
 Why wasn’t the pump working? The pump shaft was vibrating because it had worn
due to abrasion.
 Why was there abrasion? There was no fi lter on the lube pump, allowing debris
into the pump.
81

Fantasy or Wishful Thinking
A strong block to creativity is the mind’s tenacious grip on reality. One way to
stimulate creativity is to entice the mind to think in a fl ight of fancy, in the hope of
bringing out really creative ideas. This can be done by posing questions in an
“invitational way” so as to encourage an upbeat, positive climate for idea generation.
Typical questions would be:
 Wouldn’t be nice if . . . . ?
 What I really want to do is . . . .
 If I did not have to consider cost, . . .
 I wish . . .
82

FUNCTIONAL DECOMPOSITION AND
SYNTHESIS
 A common strategy for solving any complex task or describing any complex system
is to decompose it into smaller units that are easier to manage. Decomposing must
result in units that meaningfully represent the original entity.
83

Behavioral Aspects of Decision Making
 Unconflicted adherence: Decide to continue with current action and ignore
information about risk of losses
 Unconflicted change: Uncritically adopt whichever course of action is most
strongly recommended.
 Defensive avoidance: Evade conflict by procrastinating, shifting responsibility to
someone else, and remaining inattentive to corrective information.
 Hypervigilance: Search frantically for an immediate problem solution.
 Vigilance: Search painstakingly for relevant information that is assimilated in an
unbiased manner and appraised carefully before a decision is made.
85

EVALUATION METHODS
 Evaluation is a type of
decision making in which
alternatives are first
compared before making
the decision as to which is
best.
86

Pugh Concept Selection Method
 Concept Screening Method
 A relative comparison technique
 Compares each concept relative to a reference or datum concept and rate
them as better / poor / same as the reference concept
 Studies show that an individual is best in creating ideas but a small group
is better at selecting ideas.
 Thus, design team does the concept selection, usually in successive rounds
of examination and deliberation
87

Pugh selection chart for comparing the
design alternatives for redesign88

The steps in concept selection (given by Clausing) are:
1. Choose the criteria by which the concepts will be evaluated.
2. Formulate the design matrix – Criteria as rows and concepts as columns
3. Choose the datum concept: One concept is chosen as a datum for the first round – this
is the reference concept with which all other concepts are compared – choose the
better concept and mark the relevant column as DATUM
4. Run the matrix: Comparative evaluation with three level scale – better (+), worse (-) or
about the same level (S, =, 0) – appropriate symbols are put in the cells of the matrix
5. Evaluate the ratings: Sum of the +, - and = (0) ratings are determined for each concept –
All the concepts with net ‘+ve’ score are continued with, all with ‘-ve’ score are rejected
and all with same ‘0’ score are combined
89

6. Establish a new datum and re-run the matrix: New datum – Usually the
concept with the highest rating in the first round – eliminate the lowest
rating scores from the 2nd round – purpose is to verify that the
selection in Round 1 is valid
7. Plan further work: Look for missing pieces of information, calculations
or experiments that need to be made or experts that need to be
consulted.
8. Second working session: A major advantage of Pugh Concept Selection
method is that it helps the team to develop better insights into the
types of features that strongly satisfy the design requirements.
90

Concept generation and selection, viewed as
alternating divergent and convergent processes91

EMBODIMENT DESIGN
 Much of the activity at this stage is devoted to
1. Finalizing the product architecture,
2. Determining the form or shape of parts that will satisfy the
required functions,
3. Quantifying the important design parameters
 Embodiment design is also called as analytical design, as it
is the design phase where most of the detailed analysis and
calculations occurs.
Conceptual
Design
Preliminary
(Embodiment)
Design
Detail Design
92

Embodiment phase of design
 Product architecture— determining the arrangement of the physical
elements of the design into groupings, called modules.
 Configuration design —the design of special-purpose parts and the
selection of standard components, like pumps or motors.
 Parametric design— determining the exact values, dimensions, or
tolerances of the components or component features that are deemed
critical-to-quality.
93

Embodiment phase of design
 Product architecture— determining the arrangement of the physical
elements of the design into groupings, called modules.
 Four Steps of Embodiment Design
1. Create a schematic diagram of the product.
2. Cluster the elements of the schematic.
3. Create a rough geometric layout.
4. Identify the interactions between modules.
94

Configuration Design
95
Detail Design of a bolted joint

 Identify the likely ways the part might fail in service.
 Identify likely ways that part functionality might be compromised.
 Materials and manufacturing issues
 Design knowledge base
96
Configuration Design

Parametric Design
 The objective of parametric design is to set values for the design variables that will
produce the best possible design considering both performance and cost
 Robustness means achieving excellent performance under the wide range of
conditions that will be found in service.
97

Interrelationship between function and form and, in
turn, their dependence on the material and the
method of production
98

Detail Design
 Last stage of design process.
 It is the phase where all of the details are brought together, all decisions
are finalized, and a decision is made to release the design for production.
 Poor detail design can ruin a brilliant design concept and lead to
manufacturing defects, high costs, and poor reliability in service
 The reverse is not true - A brilliant detail design will not rescue a poor
conceptual design
 Detail design is the lowest level in the design abstraction hierarchy.
 Many decisions have been made to get to this point.
 Most of these decisions are very basic to the design and to change them
now would be costly in time and effort.
 Thus, detail design is mainly concerned with filling in the details to ensure
that a proven and tested design can be manufactured.
99

Chief
activities and
deliverables
of detail
design.
100

DETAIL DESIGN
 The first task of detail design is to complete the detail drawings.
 Although much of the work would have been done in Embodiment design,
still there may be some calculations to perform, questions to answer and
decisions to make.
 One important decision is - Make / Buy.
 Further, some tests have to be performed to assure that the components
and assemblies meet the requirements laid down in the product design
specification.
 As each component, subassembly and assembly is completed, it is
documented completely with detail drawings and specifications.
101

 The specifications contain information on:
The technical performance of the part
Its dimensions
Test requirements
Material requirements
Reliability requirements
Design life
Packaging requirements, and
Marking for shipment
 The specification should be sufficiently detailed to avoid confusion
at any stage.
 If the product design is complex, then it is necessary to impose a
Design Freeze at some point prior to completion.
no change permitted without approval
Design
Record
Document
102

Detail Design
 Once the design is finalized, a final prototype is built and qualification tested
to ensure that the design functions are as required, safe and reliable.
 Depending on the complexity of the product the qualification testing may
simply be to run the product during an expected duty cycle and under
overload conditions, or it may be a more elaborate series of staged tests.
 The detail drawing allow the calculation of detailed cost estimates.
 To make these calculations a bill of materials is drawn.
103

Detail Design
 Once these steps are successfully completed it is time to review the complete
product design in a final design review.
 This involves:
• Top corporate management
• The chief design personnel
• The responsible manufacturing personnel
• The customer (if the product has a defined customer)
 The successful outcome of the design review is the release of the design to the
manufacturing department
 With release to manufacturing department, detail design phase is over but Product
Development process does not end here.
 Many task are left to launch the product.
104

Detail Design
 Drawings must contain the information needed to
manufacture the product
 The drawings should be so complete that they leave no
room for misinterpretation
 The information on a detail drawing includes:
Standard views of orthogonal projection – top, front, side
Auxiliary views such as sections, enlarged views, isometric views
that aid in visualizing the component and clarifying the details
Dimensions – presented according to the GD&T standard
Tolerances
Material specification, and any special processing instructions
Manufacturing details, such as parting line location, draft angle,
surface finish
105

Planning for Manufacture
 Design for Manufacture
 Material Selection in Design
 Selection of Manufacturing Processes
106

Design to Manufacture
 Role of design in manufacturing – well realized –
Simultaneous Engineering or DFM
• All aspects of manufacturing should be kept in mind:
• Low product cost
• Low lead time
• Product quality
• The designer should capture the strength of the
manufacturing company
• Designer must have a reasonable knowledge of as
well as access to manufacturing
107

MATERIAL SELECTION IN DESIGN
 In the beginning the design is fluid and the options are wide – as the design
becomes more focused the choice is sharpened.
 Choice of material depends on
Choice of Process
Cost
The form, texture, feel, colour and decoration of the
product
Aesthetic aspects
 Good designs work but excellent design in addition to that gives pleasure
108

Material Selection
 Understand
– the potential failure modes
– the governing load conditions
 Performance Characteristics
– Physical Properties
 Density, Reflectivity
– Electrical Properties
 Conductivity
– Nuclear Properties
 Hardness, Strength, Wear
– Thermal Properties
 Conductivity, Fire resistance
– Chemical Properties
 Oxidation, Corrosion
– Fabrication Properties
 Castability, Weldability,
Machinability
109

Selection of Manufacturing Processes
 Shape generation
 Changes in internal microstructure
 Changes in properties of materials
 As Functional Decomposition of a design can be done in terms of energy, material and
information flows
 Similar is the case with manufacturing
 Energy flow is required to cause the material flow to give shape
 Information flow (both shape and material property information) depends on the type
of material, the processes used, the tooling used and the pattern of
movement of the material relative to the tooling
110

 Eight categories (Broader):
1. Solidification (Casting) Processes
2. Deformation Processes
3. Material Removal or Cutting (Machining) Processes
4. Polymer Processing
5. Powder Processing
6. Joining Processing
7. Heat Treatment and Surface Treatment
8. Assembly Processes
111

 The factors that influence the selection of a process to
make a part are:
1. Cost of manufacture and life cycle cost
2. Quantity of parts required
3. Complexity – shape, form, size
4. Material
5. Quality of part
6. Availability, lead time and delivery schedule
112

Planning for Distribution
 Important technical and business decisions must be made to provide for the
effective distribution to the consumer of the products that have been produced.
 In the strict realm of design, the shipping package may be critical.
 Concepts such as the shelf life of the product may also be critical and may need to
be addressed in the earlier stages of the design process.
 A system of warehouses for distributing the product may have to be designed if
none exists.
113

114 Planning for Use
 The use of the product by the consumer is all-important.
 The following specific topics can be identified as being important user-
oriented concerns in the design process:
• Ease of maintenance,
• Durability,
• Reliability,
• Product safety,
• Convenience in use (human factors engineering),
• Aesthetic appeal, and
• Economy of operation.
 It is becoming increasingly important with the growing concerns for consumer
protection and product safety.

115
Planning for Retirement
 The final step in the design process is the disposal of the product when it has
reached the end of its useful life.
 Design for the environment , also called green design, has become an
important consideration in design. As a result, the design of a product should
include a plan for either its disposal in an environmentally safe way or, better,
the recycling of its materials or the remanufacture or reuse of its components.

Description of design process

More Related Content

Description of design process

Editor's Notes