Workflow:%20An%20Introduction

1
WorkflowAn Introduction

• Name Alan Rubin
• Date 18/01/2003
• SDBI Course Prof. Sagiv
• Hebrew University of Jerusalem Computer Science

2
Main Points

• Goals
• Introduction
• Basic Concepts
• History
• Motivation
• Implementation Model
• Reference Model
• Workflow Patterns
• Research Topics
• Live Example
• Relevant Sources

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Goals

• To define Processes and Workflow
• To explain basic concepts of Workflow systems
• To show the history of workflow
• To exhibit the motivation behind the research and
  implementation of Workflow
• To suggest a basic architecture of a tool for the
  implementation of workflow concepts the
  workflow engine
• To suggest and enunciate ideas that can be
  research and aggregated with Workflow
• To show a live example

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Introduction

• Traditional organization of work
• Written and printed documents, reports
• Difficult for searching documents
• Difficult to maintain different versions of the
  same documents that are manipulated by many
  people
• Difficult to find who did what ?
• Difficult to track documents and processes (cause
  client dissatisfaction)

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Introduction

• Traditional organization of work (cont.)
• Difficult to transport documents
• Difficult to create a productive environment for
  user and work cooperation
• Difficult to retain and manage knowledge
• Even with arise of the computer systems it was
  difficult to perform some tasks in an organized
  manner

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Introduction

• Process
• Activities sequences done by many people
• Frequent and continuous
• Production Line X Loans (Bank) -gt Paper Industry
• There isnt a typical process
• How do processes work ?
• Traditionally inside the organization
• External requisitions Phone, Fax, E-mail
• Handling of requisitions by personnel
• Return of requisitions
• Query about current status

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Introduction

• Dynamic Global Market
• Business at every moment
• Minimal human intervention
• Business processes between different
  organizations
• Complex Interactions (E.g.. PC manufacture)
• Administration for reaction
• Processes and Workflow
• Process Model Structure in a real world
• Model is instantiated for execution
• Workflow Models
• Sections done by computersusers
• Implement part or all of the process model

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Introduction

• In a process, the right activity needs to be
  accomplished at the right time, at the right
  place, by the right people using the right tools.
  Thats Workflow...

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Basic Concepts

• Business Process Sequence of tasks done in a
  predefined order in the real world PC
  Manufacture
• Workflow Processes translated in a formal model
• Same process can have different versions
• Graphical Design
• Types Production, Autonomous, Ad Hoc and others
• User People who
• Perform tasks
• Define, modify and remove a Workflow process
  model
• Start a new Workflow process
• Stop running processes
• Access rights

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Basic Concepts

• Group Aggregation of users
• Document Important information that need to be
  passed during the Workflow execution
• Provide data protection (Access and Modification)
• Work Item Specific job that need to be done
• Can use documents, data, conditions
• Assigned to groups, users, applications or
  computers
• Can be classified in condition, split, merge,
  sub processes, start, end, regular and others
• Can have priority, date and deadline
• Can involve software applications

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Basic Concepts

• Work List List of work items assigned to some
  specific user or group
• Helps to organize users assignments (Showed by
  deadline, priority)
• Application External program/server that can
  invoked by Workflow
• Support for legacy systems
• Autonomy for task execution (no need for human
  support)
• Design vs. Instantiation of Workflow models
• One design for multiple instances
• Instances models can be modified on-the-fly
  (Versions)
• Instances can be stopped (Errors, Warnings)

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Basic Concepts

• Dimensions - W3 (or W3H)
• Process logic ? Action sequence (What ?)
• Organization dimension ? roles and people (Who ?)
• IT infrastructure ? Software resources (Which ?)
• Instructions - How ?

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Basic Concepts

• A typical process
• Holiday request
• Users
• Groups
• Documents
• Applications

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Basic Concepts

• Another typical process
• Customer Service
• Possible scenarios

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History

• Dates as far back as the mid-1970s
• Started to automate business processes
• Office automation The focus of office automation
  research was "to reduce the complexity of the
  user's interface to the office information
  system, control the flow of information, and
  enhance the overall efficiency of the office."
  Ellis, Nutt 1980, p. 28
• Research in office automation
• Flourished between 1975 and 1985
• Laid the groundwork for the development of
  industrial workflow applications through the
  analysis of technology support for administrative
  processes
• Only few academic prototypes have had an impact
  on commercial systems
• Standardization problem

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History

• Reengineering wave of the early 1990s
• Interest in process automation surged
• Wave of research prototypes between 1993 and 2000
• Commercial exploitation of workflow technology
• Began between 1983 and 1985
• Fostered by advances in imaging and document
  management technology on the one side, and
  enhanced e-mail systems that extended traditional
  point-to-point mail routing with a predefined
  process map on the other side Swenson, Irwin,
  1995.
• From this first generation of workflow systems,
  only few vendors like are still active, while the
  majority of the early players have been
  restructured through mergers and acquisitions, or
  dropped out of the market altogether. zur
  Muehlen 2003, p. 76

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History

• Workflow vs. other terms Market word game
• Business Process Management
• Heritage from Workflow
• Claims that systems and people perform the tasks
• Business Process Reengineering
• Redesign all the processes in an organization
  from scratch
• Implement all these new processes in one go

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History
History of Workflow Research
History of Commercial Workflow Systems
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Motivations

• Why Workflow ?
• Work done by the best participant
• Assembly line Vs. Once and done training and
  overhead
• Easy distribution
• Enforce completion
• Information easily accessible (No person is the
  owner)
• Knowledge management for an organization
• Logging and tracking
• Control and monitoring
• Process improvement opportunity
• Improved service (response time and client
  satisfaction)
• Privacy and security
• Integration (legacy systems and other
  applications)
• Can be executed in multiple organizations
  (Complex)

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Implementation Model

• Wfmc Worldwide Coalition
• Core value Interoperability (variety of products
  in the market)
• Founded august 1993
• Non-profit (?)
• Composed by vendors, users, analysts and
  university/research groups (285 members)
• Accomplished the publication of many technical
  papers (reference model, glossary and API
  specification)
• Three types of components (Constitute the
  Workflow system)
• Software to support internal functions
• Definitions and control data used
• External application and databases

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Implementation Model

• Need for standardization
• Continuous support for business reorganization
  and operational flexibility
• Integration requirements in consequence of the
  product specialization and market diversity
• Communication between the Workflow system and
  assorted applications

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Implementation Model
General workflow architecture
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Implementation Model
Workflow service representation
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Implementation Model
Diversified implementations for handling work
lists
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Reference Model

• Developed by Wfmc coalition
• Wfmc claims that it is used by its members
• Specialization of the generic model
• Basics
• Interfaces identification on different levels
• Interoperability
• WAPI
• Unified service interface
• Common functions in some interfaces

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Reference Model

• Workflow Engine
• Interpretation of process definition
• Control process instance and status
• Navigation between process activities, that can
  involve sequential or parallel operations, term
  synchronization and interpretation of relevant
  data
• User authentication
• Identification of work items for user
  deliberation
• Process data maintenance, assign data to the
  right applications and users
• An Interface to call external application and to
  assign data to them.
• Supervision for control, administration and audit
  purposes

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Reference Model
Status of activity instance
Status of process instance
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Reference Model
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Reference Model

• Interface 1
• Process definitions
• Normally included in product
• Shared Database
• Using of different tools for execution and
  definition
• Two aspects API and meta model
• Interface 1 Features
• Section establishment
• Operations for Workflow definition
• Operations for Workflow activity definition
• WPDL , XPDL ? XML
• Graphical Interface

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Reference Model

• XPDL XML Process Definition Language
• DTD and Schema defined by the Wfmc
• Examples
• Application_Repository.xpdl
• Business_Example.xpdl
• Participant_Repository.xpdl
• Process_Repository.xpdl

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Reference Model

• Meta model

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Reference Model
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Reference Model

• Interface 2
• Client applications of the Workflow
• Work lists
• Handling of work lists
• Tasks interface
• Interface 2 API Features
• Session establishment
• Process control functions
• Process status functions
• Work list/Work items handling functions
• Process supervision functions
• Data handling functions
• Administrative functions

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Reference Model
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Reference Model

• Interface 3
• Applications call
• From simple applications to complex ones (Email,
  Web, Delivery, Backup)
• Complex logic for potencial applications call in
  a heterogeneous enviroment
• Interface 3 API Features
• Session establishment
• Activity management functions
• Data manipulation functions

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Reference Model
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Reference Model

• Interface 4
• Interoperability Meaning ?
• Difficulties
• Interoperability Models

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Reference Model

• Main aspects
• Enforce common representation of the process
  definition
• Support for data control interchange during
  execution
• Interface 4 API Features
• Session establishment
• Operations on the processes definition
• Process control and status functions
• Activity management functions
• Data manipulation functions
• Administration functions

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Reference Model
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Reference Model

• Interface 5
• Administration and monitoring
• Performance metrics
• Interface 5 API Features
• User management functions
• Role management functions
• Audit management functions
• Resources control functions
• Process supervision functions
• Process status management

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Workflow Patterns

• Research done into commercial products
• Analogue with the design patterns by the 'Gang of
  Four
• In-depth comparison of existing workflow systems
  solutions
• Academic response to evaluations made by
  prestigious consulting companies
• Help to capture knowledge from heterogeneous
  workflow implementations
• Ideas for requirements and implementation
• Some examples will be presented
• (Paper with 20 patterns)

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Workflow Patterns

• Pattern 1 Sequence  
• FLASH Animation of pattern
• Description  An activity in a workflow process is
  enabled after the completion of another activity
  in the same process.
• Synonyms  Sequential routing, serial routing.
• Examples  
• Activity send_bill is executed after the
  execution of activity send_goods.
• An insurance claim is evaluated after the
  client's file is retrieved.
• Activity add_air_miles is executed after the
  execution of activity book_flight.
• Pattern 6 Multi-choice  
• FLASH Animation of pattern
• Description  A point in the workflow process
  where, based on a decision or workflow control
  data, a number of branches are chosen.
• Synonyms  Conditional routing, selection,
  OR-split.
• Examples  
• After executing the activity evaluate_damage the
  activity contact_fire_department or the activity
  contact_insurance_company is executed. At least
  one of these activities is executed. However, it
  is also possible that both need to be executed.

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Workflow Patterns

• Pattern 9 Discriminator  
• FLASH Animation of pattern
• Description  The discriminator is a point in a
  workflow process that waits for one of the
  incoming branches to complete before activating
  the subsequent activity. From that moment on it
  waits for all remaining branches to complete and
  "ignores" them. Once all incoming branches have
  been triggered, it resets itself so that it can
  be triggered again (which is important otherwise
  it could not really be used in the context of a
  loop).
• Examples  
• To improve query response time, a complex search
  is sent to two different databases over the
  Internet. The first one that comes up with the
  result should proceed the flow. The second result
  is ignored
• Pattern 13 Multiple Instances With a Priori
  Design Time Knowledge 
• FLASH Animation of pattern
• Description  For one process instance an activity
  is enabled multiple times. The number of
  instances of a given activity for a given process
  instance is known at design time. Once all
  instances are completed some other activity needs
  to be started.
• Examples  
• The requisition of hazardous material requires
  three different authorizations.

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Research Topics

• Using Workflow patterns to improve the engine
• Workflow calculus Can Workflow be represented
  in some algebraic way ? (Pi calculus)
• Improving resources utilization the tailors
  problem and applying it to the engine
• Workflow MultiAgents Systems (A.I.)
• Intelligent Workflow on-the-fly automatic
  workflow improvement and definition
• Scientific Workflow SpeCS (COPPE/UFRJ)
• Collaborative decision for an environment planning

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VBRWF

• Villas-Boas and Rubins WorkFlow
• Goal Implementation of a Workflow engine with an
  API Aggregation with other projects
• Used concepts of reference model Wfmc API
  Server
• Features
• Multithreading (Many requests same time)
• Communication API-Server Isolation with sockets
• XML or API for process definition (Subset of
  XPDL)
• OS independent
• Server (C OO) and API (C and Java OO)
• Possibility of implementation in Web or GUI
  projects
• Current Status
• Working
• Some functions implemented from Interfaces 1, 2
  and 5
• Complexity 33 Tables, 27 API Classes and 9
  Server Classes

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Live Example

• jBpm
• Open source (Apache License)
• Flexible and extensible workflow management
  system
• J2EE application (JBoss)
• jPdl for language definition
• Based on workflow patterns
• The demo Users and Groups
• Albert Einstein and Carl Gauss ? 'Research and
  Development
• Carl Gauss ? boss of 'Research and Development
• Pierre De Fermat ? 'HR-responsible' for the
  'Research and Development'

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Live Example

• The demo The holiday process
• Allows users to manage planned absences
• Every employee is able to request a holiday
• The requester has to enter the start date, end
  date and a comment
• Then this request is presented to the boss of the
  requester
• The boss evaluates
• If the holiday is approved, both the
  HR-responsible and the requester are informed
• If the holiday is disapproved, only the requester
  is notified
• Execution

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Relevant Sources

• Workflow Patterns
• Wfmc
• Workflow Research
• JBpm
• Book Production Workflow
• SpeCS

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The End

• Thanks for your attention !
• Questions ?