WorkFlow Management Systems

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WorkFlow Management Systems

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A Process is a set of activities that must be completed to produce a result valued by the customer

A Process can be any part of an organization that takes inputs and transforms them into outputs

What is a Business Process ?

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What is a Work-Flow ?

Automation of a business process, in whole or part, during which documents, information or tasks are passed from one participant to another for action, according to a set of procedure rules (WFMC)

Standards set by WorkFlow Management Coalition (WFMC)

http://wfmc.org

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Business Process Example

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Workflow entities

Documents, Data and Activities (Tasks)

Participants or Agents

Predefines set of rules

Business Process description as

representation of Coordination of agents

and activities

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Workflow Examples

Loans Management

Orders Management

Human Resource Evaluation

Weekly data sheets

Evaluation of credit requests

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Workflow Automation

Technologies for automating business processes management

Groupware supporto team-work (es.: shared editing

of documents)

Workflow Management System (WFMS)Automated Execution of a Business

Process

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Software System used for:

defining business processes (workflow)

create, manage and execute workflows

Interact with workflow participants

invoke applications and external software agents

Manage process instances

– Many instances of the same business process can be executed in the same time

– Each instance has its own data and participants

Workflow Management System

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WFMS

Five main WFMS functions:

Business process execution

Documents/Activity assignment

Monitoring and control

Notification and queues

Task assignments and automation

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WorkFlow Management Coalition WFMC

The WorkFlow Management Coalition (www.wfmc.org)

consortium of WFMS providers

Users and analysts

Goal: define standards for WFMS

Standard notations (XPDL)

Standard terminology

Standard protocols among WFMS and external applications

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WFMS main features

Build-time functions

Definition and modeling of business process and activites

Run-time control functions:

business process execution

Activiation of activities as aprts of a business process

Run-time interactions

With users and other applications

Among different activites in a business process

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WFMS features

Process

Definition

Build Time

Business Process Analysis,

Modelling & Definition Tools

Run Time

Workflow Enactment Service

Process changes

Process Instanciation

& Control

Applications

& IT Tools

Interaction with

Users & Application Tools

Process Design

& Definition

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Relationships among Workflow concepts

Business ProcessDesign

Business ProcessExecution

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Process Definition

Modeling of business process

For analysis, evaluation and simulation

To be executed in a WFMS

Process Definition consists in:

An activity diagram

Process’ Start/Stop Criterias

Activity Data

participants (actors)

documents and related data

External Applications used by the process

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Business Process Languages

BPEL

Business Process Execution Language

BPML

Business Process Modelling Language

XPDL

XML Process Definition Language

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Languages (BPEL)

BPEL (Business Process Execution Language) allows to define abstract and executable processes

BPEL is supported by the majority of companies

When using BPEL, software already exists (from several vendors) on which such processes can be executed (BPEL servers) and developed (BPEL designers).

BPEL follows the orchestration paradigm: a central process takes control over the involved services.

BPEL was developed by IBM and Microsoft, but it was finally submitted to OASIS, thus creating the WSBPEL (Web Services BPEL).

A BPEL process consists of activities connected by links

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Languages (BPML) BPML (Business Process Modelling Language)

Supported by the Business Process Modelling Initiative is "a meta-language for the modelling of business processes, just as XML is a meta-language for the modelling of business data".

BPML provides an abstracted execution model for collaborative and transactional business processes that span multiple applications and business partners.

The specification is quite similar to BPEL but BPML also supports the scheduling of tasks at specific times.

It also supported persistence, roles, instance correlation and recursive decomposition.

BPML supports mechanisms to handle exceptions as well as long and short running transactions.

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XPDL Language The XML Process Definition Language (XPDL) is a

format standardized by the WfMC to interchange business process definitions between different workflow products like modelling tools and workflow engines.

It is a file format defined by a XML Schema that represents the "drawing" of the process definition

It has X & Y coordinates and node size. It has a concept of lines, and points along the line that give it a particular path. The nodes and lines have attributes which can specify executable information such as roles, activity descriptions, timers, web service calls, etc.

XPDL is extensible. Each tool has specialized requirements on the diagram, it can represent these using extended attributes.

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Workflow Participant (Actor)

It is an agent executing the task associated to a particular activity instance

When a task is assigned to an actor it is inserted in the Actor’s WORKLIST

WORKLIST is an ordered list of task to be done

Each actor has a worklist

Participant can be:

A human resource

A software application

A specific hardware

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Process Instances and WorkLists

Business process is defined with a language

A Process Instance is created

Process Istance is composed by many tasks

Each task is assigned to one or more actors

A Work-List is a list of Work-Item (task) that must be executed by an actor

A work-list per actor

An actor can represent a group of actors sharing a common task

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Execution examples

Work List 1

Work Item 1

Work Item 2

Work Item 3

Process Definition Process Instance Worklist

Activity B

1st Process Instance

2nd Process Instance

3rd Process Instance

Activity DActivity A

Activity C

Process Definition A

Activity B

Activity D

Activity A Activity C Activity E

Process Definition BWork Item 20

Work Item 22

1st Process Instance

2nd Process Instance

Work Item N

Work Item N

Work Item 4

Work Item 21

Work List 2

Work List 1

Work List 2

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WFMS Architecture

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Other Workflow

Enactment Service(s)

Workflow API and Interchange

formats

Workflow

Engine (s)


Process

Definition Tools

Workflow Client

Applications

Invoked

Application

Administr. &

Monitoring

Tools

Interface 1

Interface 5Interface 4

Interface 3Interface 2

Workflow

Engine (s)

Reference Model

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WorkFlow Engine

Different WFMSs (Workflow engines) can beused to execute a business process

Software Applications can interact with WFMSthrough the Workflow ApplicationProgramming Interface (WAPI).

A process instance can be executed

In a single WorkFlow engine

Or on different WorkFlow engines

– Using WFMC interoperability interface

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Interaction with external resources

client application interface (2)

Defines WorkFLow Client interactions

– (e.g. show worklist)

invoked application interface (3)

WF engine can invoke external apps to perform an activity

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Applications &

IT Tools

Business Process Analysis

Modelling & Definition Tools

Process editing

Build time

Run Time

Run Time

Workflow control data

Workflow relevant data

Application data

Definizione processi

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Process Analysis

Modelling & Definition

Tools

Process Definition

Interchange

Format & APIs

Workflow

Engine (s)


Process Definition Interface (itf 1)

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Workflow

Engine (s)

Client

ApplicationInvoked

Application

User Interface

Command Set

Connection/Disconnection

Process and Activity Control

Functions

Process Status Functions

Worklist Manipulation

Commands

Client Application Interface (itf 1)

Standard APIs & Interchange

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Workflow

Engine (s)

Application

Agent

Invoked

Application

Workflow-

enabled

Applications

Standardised APIs &

Interchange

Application Specific

Interfaces

(Local or Remote)

Invoked Application Interface

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Defined by Workflow Coalition to enable

communciation among different WFMS

4 interoperability models

Chained-Services Model

Nested Process Model

Peer-peer model

Synchronized Parallel Model

Workflow Interoperability (itf 4)

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Activity or sub-process invocation

Process / Activity status / control

Application / Workflow relevant data transfer

Synch-point coordination

Process definition read / write

Workflow API and Interchange format


Workflow API and Interchange format


Workflow

Engine (s)

Workflow

Engine (s)

Workflow Interoperability Interface

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Allows transfering a single activity betweentwo WFMS engines• they work indipendently after the transfer• without any other synchronization

A1A4

A2 A3

A5 B1B3

B4

B2

B5

Process A Process B

Chained-Services Model

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• Activity (A3) of process A executed as a B process in WF B engine

•Control returns to A when B is ended

A1A4

A2 A3

A5 B1B3

B2

B4 B5

Processo BProcess A

Domain of Workflow

Service A

Domain of Workflow

Service B

Nested Process Model

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C1C4

C2 C3

C5 C6

• Shared Execution of a

Process, whose activities are

splitted and executed on 2

engines

• E.g.: C1,C2,C5 executed by A

C3, C4 , C6 executed by B

Both WF must:

• Support a common

communication interface

• Be able to interpret a process

model

• Import an external BP model -

transfer data at run-time

Workflow

Engine (s)

A

Workflow

Engine (s)

B

Peer-Peer Model

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Two processes work indipendently

One waits the other when Synchronization

Point is reached

A1A4

A2 A3

A5 B1B3

B2

B4 B5

Process BProcess A

Domain of WFMS A Domain of WFMS B

Synchronization

Point

Parallel synchronized Model

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Managent

Application

Workflow

Engine (s)


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WAPI

Interface 5

Workflow

Engine (s)


BTypical Functional Areas

User management

Role management

Audit management

Resource control

Process supervisory functions, etc

Systems Admin. & Monitoring Interface