Workflow Automation: Applications, Technology and Research

Origins of Workflow

Ten years ago, a team of engineers conceived the idea that computer software could be used to automate paper-driven business processes. They called it "workflow software." [Smith 93] imaging document flow enhanced emails workgroup support multi-system apps.

About 200 products claim to support workflow features and/or workflow management!

See [2] and [Georgakopoulos,Hornick,Sheth 95] for a list of vendors and products.

Overview of Current Commercial State-of-the-Art

• Emphasis on office processes: -imaging -document flow -enhanced mail • Reasonable support for administrative and ad-hoc workflows • Many products are little more than fancy diagramming tools (Dataflow, Digraph, Flowchart, Network, Orgchart, Pertchart,...), with layout support, capture/import/export of data from/to databases, spreadsheets, simulation tools • Some are specialized electronic data management systems: e-mail, imaging, databases, electronic forms, text, engineering drawing,.. • Alliances between image/document management, GUI builder and tools companies (e.g., simulation) are common

Workflow Management System for

Office Automation vs Enterprise Automation (Typical Case) Current workflow/workgroup software supports office automation functions (involving user tasks) (most products are in PC and mainframe env.). There is little support for application automation (involving both user and application tasks with varied level of transactional properties).

On Transactional Workflows

Transactional workflows are activities that involve coordinated execution of multiple related tasks on distributed/heterogeneous/autonomous information systems and support (provide) selective use of transaction properties at individual task and (intra-and inter-) workflow levels.

In particular, they use transaction management concepts and technology for specifying and ensuring workflow correctness and reliability in distributed/heterogeneous/autonomous information system environments.

More on this later... [ • defining workflows, i.e., describing those aspects of processes that are relevant to controlling and coordinating the execution of its tasks (and possibly the skills of individuals or information systems required to perform each task), and

• providing for automation and re-engineering (fast (re)design and (re)implementation) of the processes as business needs and information systems change. [ 1.preparation -a customer requests an action to be performed or a performer offers to do some action 2.negotiation -both customer and performer agree on the action to be performed and define the terms of satisfaction 3.performance -the action is performed according to the terms established 4.acceptance -the customer reports satisfaction (or dissatisfaction) with the action

Types of Tasks

• user tasks involving humans in processing task • application tasks:

• scripts involving terminal emulations to remote systems • predefined interfaces to legacy application systems (e.g., Bellcore "contracts") • stored procedure calls • client programs or servers invoking other servers • database transactions [ Workflow management can be seen as a new distributed computing paradigm...

Workflow Model and WMS wish list (Requirements and Features)

• Modeling heterogeneous tasks -task behavior/structure: externally visible states of the task, initial state, termination states, significant events and their attributes -task inputs and outputs -task (operation) semantics, e.g., compatibility, relaxed isolation

• Modeling Interfaces and Processing Entities:

-type of interface/processing entity: communication infrastructur(s) and associated APIs -interface/processing entity (system) properties/semantics-e.g., isolation granularity, order preservation, idempotency, monotonicity [

Scheduling Approaches

• Based on Petri-net Models [Elmagarmid et al 90] • Executor for Flex. Trans. in a logically parallel language L.0 [Ansari et 92] • Interpreter of MDB transaction specification Language (VLP) [Kuehn et al 91] • Interpreter of ECA rules [Dayal et al 92] • Games vs. Nature [Rusinkiewicz et al 92] • Fine-state Automata [

Transactional Workflow--What it is and is not

Transactional workflows (try to) address application specific and user-defined correctness, reliability, and functionality requirements.

Transactional workflows share the objectives of some extended/relaxed transaction models about selective relaxation of transactional properties based on application semantics.

... the term is likely to evolve, as it has significant appeal. For Typically WMSs do not support some of the important features supported by TP Monitors (e.g., concurrency control, backward recovery, consistency of data). WMSs today do not support concurrency control similar to those involved between "transaction groups" in TP monitors. WMS applicationsoften rely on local concurrency control.

A WMS may provide transactional properties to support forward recovery, and/or use system and application semantics to support semantic-based "correct" multi-system application execution. Example levels of transactional support a WMS may provide are: -use of TM concepts/techniques (log input/output, before image, compensation...) to enable forward recovery and failure atomicity -part of a workflow has transactional properties (extended transactional model with component transactions) -support a "general" two phase commit (WMS schedule may provide commit coordination) or interface with an external commit coordinator.

A WMS may use transaction management technology, such as -transactional-RPC between two components of a WMS (e.g., scheduler and task manager), -an external commit coordinator -XA-like protocol between task manager and resource manager (Interface/Proc. Ent.).

LSDIS

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Multi-paradigm Workflows

Workflow applications in large/complex enterprises and those spanning multiple enterprises require support for multiple paradigms in terms of: • Types of workflows: production, ad-hoc,...

• Communication infrastructures:

-Async (e-mail, document flow/work-group based, message based) -Sync (PRC, t-RPC, ...) -local-area --internet -wireless • Computing Structures/Semantics: e.g., transactions in Electronic Commerce, Transaction Processing Systems, and DBMSs

Trends/Standardization Efforts

Horizontal "Interoperability" Focus -Workflow Coalition--lack of "information system" perspective and "transaction" support so far

Conclusions

• New paradigm for distributed computing? Perhaps it is the way to provide glue to handle legacy systems, and to to support migration/evolution. • Technology related to business processes and applications--better relevance and visibility than heterogeneous DDBMS and extended transactions; still database and transaction management have important roles to play. Dr. Amit Sheth directs the Large Scale Distributed Information Systems (LSDIS) Lab and is an Associate Professor of Computer Science at the University of Georgia. Earlier he worked for nine years in the R&D labs at Bellcore, Unisys, and Honeywell. He has lead projects on heterogeneous DDBMS, factory information system, integration of AI-database systems (BrAID), transactional workflows (PROMT and METEOR), federated database tools (BERDI and TAILOR), multidatabase consistency, and data quality (Q-Data). Dr. Sheth has published over 75 papers, given over 45 invited talks and 14 tutorials, and lead two international conferences and a workshop as a General/Program (Co-)Chair. He has also served twice as an ACM Lecturer, has been on over twenty five program and organization committees, and is on the editorial board of four journals.

The LSDIS lab maintains very active collaboration with industry, and has won significant projects in the areas of interoperable information system and workflow management (under the Healthcare Information Infrastructure Program awarded by NIST) and global information system and management of heterogeneous digital data (awarded in the Massive Digital Data Systems initiative). Industrial partners on these projects are Bellcore, MCC and CHREF. The lab acknowledges sponsorship/industrial affiliation of the HP Labs and the Persistence Software Inc.