Workflow Management | Course Paper

Workflow Management Coalition

The Workflow Reference Model

Document Number TC00-1003

Document Status – Issue 1.1

19-Jan-95

Author:

David Hollingsworth

Send comments to d.c.hollingsworth@x400.icl.co.uk

Workflow Management Coalition

2 Crown Walk

Winchester

Hampshire, UK

SO22 5XE

Tel: (+44) 1962 873401

Fax: (+44) 1962 868111

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

Email: WfMC@wfmc.org

Web: http://www.wfmc.org

Table of Contents

1. Introduction…………………………………………………………………………………… 3

1.1. Background……………………………………………………………………… 3

1.2. Purpose…………………………………………………………………………… 3

1.3. Scope……………………………………………………………………………… 3

1.4. Audience…………………………………………………………………………. 4

1.5. How to read this document …………………………………………………. 4

1.6. Cross References………………………………………………………………. 4

1.7. Revision History ………………………………………………………………. 4

2. Workflow Systems Overview……………………………………………………………. 6

2.1. What is Workflow?…………… ……………………………………………… 6

2.2. The Evolution of Workflow ………………………………………………..10

2.3. Product Implementation Model ……………………………………………12

2.4. Alternative Implementation Scenarios …………………………………..15

2.5. The Need for Standardisation ……………………………………………..18

3. Workflow Reference Model ……………………………………………………………..20

3.1. Overview ………………………………………………………………………..20

3.2. The Workflow Model ………………………………………………………..20

3.3. Workflow Enactment Services…………………………………………….21

3.4. Process Definition …………………………………………………………….28

3.5. Workflow Client Functions…………………………………………………31

3.6. Invoked Application Functions ……………………………………………35

3.7. Workflow Interoperability ………………………………………………….37

3.8. Systems Administration……………………………………………………..44

4. WAPI Structure, Protocols & Conformance ………………………………………..46

4.1. WAPI – Functional Overview of APIs…………………………………..46

4.2. WAPI Protocol Support …………………………………………………….47

4.3. Conformance Principles……………………………………………………..48

4.4. Interoperability Classifications & Conformance Levels ……………48

Appendix – Glossary of Terms and Abbreviations …………………………………….51

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

1. Introduction

1.1. Background

Work Flow Management is a fast evolving technology which is increasingly being

exploited by businesses in a

variety of industries. Its primary characteristic is the automation of processes involving

combinations of human

and machine-based activities, particularly those involving interaction with IT applications

and tools. Although

its most prevalent use is within the office environment in staff intensive operations such as

insurance, banking,

legal and general administration, etc, it is also applicable to some classes of industrial and

manufacturing

applications .

Many software vendors have WFM products available today which involve WFM

technology and there is a

continual introduction of more products into the market. The availability of a wide range

of products within the

market has allowed individual product vendors to focus on particular functional

capabilities and users have

adopted particular products to meet specific application needs. However, there are, as yet,

no standards defined

to enable different WFM products to work together, which is resulting in incompatible

“islands” of process

automation.

The WFM Coalition is a grouping of companies who have joined together to address the

above situation. It has

been recognised that all work flow management products have some common

characteristics, enabling them

potentially to achieve a level of interoperability through the use of common standards for

various functions.

The WFM Coalition has been established to identify these functional areas and develop

appropriate

specifications for implementation in workflow products. It is intended that such

specifications will enable

interoperability between heterogeneous workflow products and improved integration of

workflow applications

with other IT services such as electronic mail and document management, thereby

improving the opportunities

for the effective use of workflow technology within the IT market, to the benefit of both

vendors and users of

such technology.

1.2. Purpose

The purpose of this document is to provide a framework to support the development of the

various

specifications described above. It provides a common “Reference Model” for workflow

management systems

identifying their characteristics, terminology and components, enabling the individual

specifications to be

developed within the context of an overall model for workflow systems. The detailed

specifications will be

developed as separate documents.

1.3. Scope

This document covers the concepts, terminology, general structure of a workflow

management system, its

major functional components and the interfaces and information interchange flows

between them. It identifies

the areas appropriate for standardisation and illustrates the potential interoperability

scenarios which may be

supported through the use of common standards. It also discusses, where appropriate, the

applicability of

existing standards to workflow management systems and their integration with other

standard IT services. It

does not cover wider aspects of business process engineering which lie outside the use of

information

technology to support the business process.

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

1.4. Audience

The intended audience of this document is the work flow coalition membership as well as

others that are

interested in the efforts of the coalition and wish to understand the top level technical

architecture which

underpins the work of the Coalition. The document is intended for a moderately technical

audience but

extensive prior knowledge of workflow systems is not assumed.

1.5. How to read this document

Chapter 2 provides a general introduction to the concepts of workflow systems technology,

its evolution, the

business context and background on the types of systems which may incorporate this type

of technology. If you

are unfamiliar with workflow technology you should start here; if you are already familiar

with workflow

management systems, consider starting at Chapter 3.

Chapter 3 discuses the internal structure of workflow systems, the major functional

components and the nature

of their interactions. It introduces the top level architecture and identifies the various

interfaces which may be

used to support interoperability between different system components and integration with

other major IT

infrastructure components.

Chapter 4 provides a general overview of the workflow application programme interface

(WAPI), comments on

the necessary protocol support for open interworking and discusses the principles of

conformance to the

specifications. It identifies those aspects of the specifications which are required to support

various classes of

interoperability. The detailed WAPI specifications are published as separate specification

documents (see cross

references below).

1.6. Cross References

WFMC SC00 – 1002 WFM Coalition Proposal Information

WFMC SC00 – 1006 WFM Coalition Technical Committee Operations

WFMC TC00 – 1008 Interoperability White Paper

WFMC TC00 – 1009 Client application API descriptions

WFMC TC00 – 1010 Workflow Definition Read/Write Descriptions

WFMC TC00 – 1011 Terminology and Glossary

WFMC TC00 – 1013 Workflow APIs – Naming Conventions

1.7. Revision History

This issue (1.1) is the second major version, incorporating the following changes from the

previous version

(0.6):

*ƒ‚· Incorporation of updated terminology and glossary

*ƒ‚· Incorporation of monitoring and metrics interface within the reference model

*ƒ‚· Updated material on workflow interoperability (derived from the Coalition work on

the Workflow

Interoperability White Paper) and its associated interface operations, clarifying the various

interoperability

scenarios and proposed areas for open interoperability

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

*ƒ‚· Incorporation of comments on the (optional) use of organisational roles within the

basic model

*ƒ‚· Incorporation of comments clarifying the use of workflow relevant data within the

basic model

*ƒ‚· Incorporation of minor changes to align with the output of other Coalition Working

Groups, particularly

the initial API specifications

*ƒ‚· Improvements in clarification and consistency in various areas throughout the text,

including amended

document structure

Version 1.1 incorporates minor editorial changes as a result of the TC meeting in Vienna

(10th Nov 94), plus

revisions to improve consistency with other Coalition documentation.

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

2. Workflow Systems Overview

2.1. What is Workflow?

Workflow is concerned with the automation of procedures where documents, information

or tasks are passed

between participants according to a defined set of rules to achieve, or contribute to, an

overall business goal.

Whilst workflow may be manually organised, in practice most workflow is normally

organised within the

context of an IT system to provide computerised support for the procedural automation and

it is to this area

that the work of the Coalition is directed.

Definition – Workflow

The computerised facilitation or automation of a business process, in whole or part.

Workflow is often associated with Business Process Re-engineering, which is concerned

with the assessment,

analysis, modelling, definition and subsequent operational implementation of the core

business processes of an

organisation (or other business entity). Although not all BPR activities result in workflow

implementations,

workflow technology is often an appropriate solution as it provides separation of the

business procedure logic

and its IT operational support, enabling subsequent changes to be incorporated into the

procedural rules

defining the business process. Conversely, not all workflow implementations necessarily

form part of a BPR

exercise, for example implementations to automate an existing business procedure.

A Workflow Management System is one which provides procedural automation of a

business process by

management of the sequence of work activities and the invocation of appropriate human

and/or IT resources

associated with the various activity steps.

Definition – Workflow Management System

A system that completely defines, manages and executes workflows through the execution

of software

whose order of execution is driven by a computer representation of the workflow logic.

An individual business process may have a life cycle ranging from minutes to days (or

even months), depending

upon its complexity and the duration of the various constituent activities. Such systems

may be implemented in

a variety of ways, use a wide variety of IT and communications infrastructure and operate

in an environment

ranging from small local workgroup to inter-enterprise. The WFMC Reference Model thus

takes a broad view

of workflow management, which is intended to accommodate the variety of

implementation techniques and

operational environments which characterise this technology.

Despite this variety, all WFM systems exhibit certain common characteristics, which

provide a basis for

developing integration and interoperability capability between different products. The

Reference Model

describes a common model for the construction of workflow systems and identifies how it

may be related to

various alternative implementation approaches.

At the highest level, all WFM systems may be characterised as providing support in three

functional areas:

TC00-1003 Issue 1.1 Workflow Reference Model Printed 19/11/98

*ƒ‚· the Build-time functions, concerned with defining, and possibly modelling, the

workflow process and its

constituent activities

*ƒ‚· the Run-time control functions concerned with managing the workflow processes in

an operational

environment and sequencing the various activities to be handled as part of each process

*ƒ‚· the Run-time interactions with human users and IT application tools for processing the