Functions and Architecture of Workflow System

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Functions and Architecture of Workflow System
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Role of Workflow Management Systems

• Information systems must meet a number of
  requirements
• IS must set up in such a way that the structure
  of the business processes is clearly reflected.
• There should be an integrated approach, which
  also encompasses non-computerized tasks.
• IS must be set up in such a way that the
  structure of the business processes can easily be
  modified.
• The performance of a business process can be
  tracked properly, so that any problems can be
  discovered at an early stage.
• Good workload management is crucial to achieving
  effective and efficient business processes.

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Role of Workflow Management Systems

• How information systems are traditionally
  structured?
• Process management has not been separated from
  the application software in information systems.
• The process management has been hidden inside the
  information system.
• Little attention been paid to process structure
  within the framework of traditional systems, it
  has often been difficult to actually recognize
  the business process.
• The process contained in the system has sometimes
  been incorrect or incomplete.

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Role of Workflow Management Systems
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Role of Workflow Management Systems

• Advantages--
• This makes it possible to reuse the same
  functionality in more than one task.
• This makes it possible to rearrange the business
  process at a later stage.
• In this way, it is even possible to integrate new
  applications with legacy systems.
• The process execution is more manageable, with
  progress and bottlenecks being more easy to check.

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A REFERENCE MODEL

• WFMC,1996
• Workflow Enactment Service
• Process Definition Tools
• Workflow Client Applications
• Invoked Applications
• Other Workflow Enactment Services
• Administration and Monitoring Tools

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A REFERENCE MODEL
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Workflow Enactment Service

• The heart of a workflow system.
• The Enactment Service may consist of several
  workflow engines.
• Workflow engine
• creating new cases and removing completed ones.
• routing cases, using the interpretation of the
  appropriate process definition.
• submitting work items to the correct resources
  (employees), based upon resource
• classification.
• managing and handling triggers.
• starting up application software during the
  performance of an activity.
• recording historical data.
• providing a summary of the workflow.
• monitoring the consistency of the workflow.

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Process Definition Tools

• The process definition tool
• The resource classification tool
• The analysis tool

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Process Definition Tools

• Ability to establish process definitions (name,
  description, date, version, components, and so
  on).
• Ability to model sequential, parallel, selective
  and iterative routing by means of such graphic
  components as the AND-split, AND-join, OR-split
  and OR-join.
• Version-management support (after all, there may
  be several versions of the same process) .
• Definition of case attributes used in the process
  .
• Task specification.
• Checking of the (syntactical) correctness of a
  process definition and the tracing of any
  omissions or inconsistencies.

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Process Definition Tools

• The following is established for each task
• name and description of the task
• task information - any instructions and
  supporting information for the employee
  performing the task
• the requirements with respect to the resource
  carrying out the task (for example, a
  specification of its role and organizational
  unit, or information about the separation of
  functions)
• the task's routing characteristics (AND-split,
  AND-join, OR-split, OR-join)
• the specification of any triggers required
• instructions for the workflow engine (for
  example priorities, case management and resource
  management)

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Process Definition Tools

• The resource classification tool
• A list of the resource classes, often subdivided
  into roles (based upon qualifications, functions
  and skills) and organizational units (based upon
  arrangement into teams, branches and/or
  departments).
• Any specific characteristics of a resource class.
• Relationship between the various resource classes
  (for example, a hierarchy of roles or
  organizational units).

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Process Definition Tools

• The analysis tool
• Before a workflow which has been defined can go
  'into production', it is first useful to analyze
  it.

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Workflow Client Applications

• The standard worklist handler
• The standard worklist handler offers the
  functionality just described.
• The integrated worklist handler
• This specific worklist (customized worklist
  handler) handler would contain supporting
  facilities alongside the standard functionality
  described above
• Ex processing similar cases in batch processing
  a series of successive tasks for a case

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Worklist Handler
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Invoked Applications

• Interactive application (ex. word, excel)
• Fully-automatic application (ex. calculation)

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Other Workflow Enactment Services

• A workflow system may contain several workflow
  engines.
• These come under the same management and use the
  same workflow definitions.
• Such engines are said to belong to the same
  workflow domain.
• However, it is also possible to link several
  autonomous workflow systems with one another.
• cases (or parts of cases) can be transferred
  from one system to another.
• This means that the Workflow Enactment Services
  of each system are linked. We refer to this as
  workflow interoperability.

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Administration and Monitoring Tools

• The operational management tool
• Not case-related (resource-related or
  system-related)
• addition or removal of staff
• input/revision of an employee's details (name,
  address, telephone number, role, organizational
  unit, authorization and availability).
• Case-related
• inspection of the logistical state of a case
• manipulation of the logistical state of a case
  due to problems and exceptional circumstances.

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Administration and Monitoring Tools

• The recording and reporting tool
• These are historical data which may be useful for
  management. For example, the following
  interesting performance indicators may be
  distilled from the data
• average completion time for a case
• average waiting time and processing time
  (possibly subdivided per task)
• percentage of cases completed within a fixed
  standard period
• average level of resource capacity utilization.

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Components of a Workflow System
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Users of a Workflow Management System
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Roles of people involved

• Workflow management system
• The Workflow Designer
• The Administrator
• The Process Analyst
• The Employee
• Applications
• database designers/programmers
• application designers/programmers

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Data in a workflow system
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Interfacing problems

• WFMC recognizes five interfaces
• Improve the exchange of data.
• Create links between servers in a simple way.
• Applications are entirely independent of the
  workflow management system.
• Every interface will be achieved using
  Application Programming Interface (API).

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Interfacing problems (cont.)

• Interface 1
• Connect/disconnect
• Process definitions and resource classifications
• Opening, creating and saving a process
  definition

• Interface 5
• Management
• Addition of an employee
• Permission of authorization
• Execution of a process definition
• Track
• Waiting times
• Completion times
• Processing times
• Routing
• Staff utilization

Interface 4 Other Workflow Enactment Services

• Interface 2
• Connect/disconnect production of case
• Work item state summaries
• Generation of new cases
• Beginning, interruption and completion of
  activities

• Interface 3
• Application is opened from the system through
  interface 3. (also can opened from the worklist
  handler)

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Interfacing problems (cont.)
An application can be started by an engine and/or
from a worklist handler.
An application is called to perform a task.
If the workflow engine does not become accessible
following the execution of the Application due to
a system error, the engine and the application
will be 'out of synch.
Once the system has been corrected, the engine
will have no choice but to roll back the task.
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Interfacing problems (cont.)

• Atomicity
• Completed in full (Commit).
• Restarts from the very beginning (Rollback).
• Consistency
• The result of an activity leads to a consistent
  state.
• Isolation
• Tasks performed at the same time must not
  influence one another.
• Durability
• Task is successfully completed.
• The result must be saved.
• Completed with a commit.

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Interfacing problems (cont.)

• In the financial world, we frequently have to
  pass the ACID test.
• Linking two or more workflow systems, most of
  the workflow management systems is not always
  entirely clear what the state of a case is.

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Interoperability standards

• Interoperability specification
• Specifications for workflow modeling and workflow
  description (i.e., design-time)
• Specifications for runtime interoperability.

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Interoperability standards (cont.)

• Design-time
• WPDL (WFMCs Process Definition Language
  )(Interface 1Process Definition Tools)
• PIF (Process Interchange Format)
• Process descriptions can be exchanged
  automatically without using different translators
  for each pair of systems.
• Process modelers
• Workflow systems
• Process repositories
• PSL (Process Specification Language ) by NIST

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Interoperability standards (cont.)

• Runtime
• Interface
• Interface 2 Workflow Client Application
• Interface 3 Invoked Application
• Interface 4 Other Workflow Enactment Service
• Standards
• WFMC
• SWAP
• WF-XML
• OMGs jointFlow

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Required Technical Infrastructure

• Most workflow system operate within a
  client/server environment.
• Client
• Worklist handler
• User Interface
• Application
• Server
• Workflow engine
• Application
• DBMS
• Application data

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Required Technical Infrastructure
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Current Generation of Workflow Product

• Product in 2000?200 suppliers
• The number of workflow systems actually in
  production is relatively limited.
• Why?
• The technology is quite new.
• Resulting in limited functionality and
  unsatisfactory reliability.

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Current Generation of Workflow Product

• Staffware
• Graphical Workflow Definer (GWD)
• Graphical Form Designer (GFD)
• Work Queue Manager (WQM)
• Staffware Server (SS)
• Staffware Administration Managers (SAM)
• Audit Trail (AT)

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Current Generation of Workflow Product
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Current Generation of Workflow Product

• GWD
• The tasks are called steps.
• Automatic steps
• Normal steps
• Event steps
• Semantics
• Step
• OR-join/AND-split
• Wait
• AND-join/AND-split

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Current Generation of Workflow Product

• Condition
• OR-split? two choice
• Compare with Petri net
• Concepts such as AND/OR-split/join play an
  important role in both types of models.
• One of the core differences is the fact that the
  notion of states.

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Current Generation of Workflow Product

• Problem
• Models become larger.
• Several constructs which can be modeled in terms
  of Petri nets cannot be modeled in
  Staffware.(external application)

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Current Generation of Workflow Product

• Figure 5.11 does not consider two additional
  features
• It is possible to withdraw steps.
• It is possible to model time-outs.

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Current Generation of Workflow Product
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COSA

• COSAR (COmputerunterstutze SAchbearbeitung) is
  produced by Software-Ley GmbH.
• It is a workflow management system based upon
  Petri nets.
• COSA can be described as a traditional workflow
  management system that closely follows the WFMC
  reference model.

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COSA (cont.)
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COSA (cont.)

• 1.COSA Network Editor (CONE)
• CONE is a process definition tool for defining
  and revising processes. (Figure 5.15)
• 2.COSA User Editor (COUE)
• COUE is a resource classification tool for
  defining roles and organizational units. (Figure
  5.16)
• 3.COSA MemoBox (COMB)
• COMB is a standard worklist handler for offering
  and starting work items.
• 4.COSA Networkstate Displayer (COND)
• COND is a graphic tool for presenting the state
  of a case.

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COSA (cont.)

• 5.COSA Runtime Server (CORS)
• The CORS is a workflow enactment service which
  consists of one or more engines.
• 6.COSA Simulator (COSI)
• COSA offers a primitive tool for simulating
  business processes.
• 7.COSA Administrator (COAD)
• COAD is used to manage the workflows.
• COSA does not offer a recording and reporting
  tool.
• COSAs architecture can easily be mapped onto the
  WFMC reference model.

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ActionWorkflow

• ActionWorkflowR is produced by Action
  Technologies Inc., and focuses upon supporting
  processes in which communication between people
  and/or parties plays a major role.
• Unlike COSA and Staffware, which concentrate upon
  the process, ActionWorkflow centers on
  coordination.
• ActionWorkflow uses so-called Business Process
  Maps (BPM).
• Each workflow corresponds with a transaction that
  passes through the following stages
• (1) preparation
• (2) negotiation
• (3) performance
• (4) completion

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ActionWorkflow

• Transitions between these stages take place using
  so-called speech acts (communication between the
  people/parties involved in the transaction).
• ActionWorkflow 3.0, also know as the
  ActionWorkflow Enterprise Series, consists of the
  following components
• 1.ActionWorkflow Process Builder
• 2.ActionWorkflow Process Manager
• 3.Action DocRoute
• 4.Action Metro

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ActionWorkflow(cont.)

• 1.ActionWorkflow Process Builder
• The Process Builder is used to illustrate
  workflows, with the aid of Business Process Maps.
• 2.ActionWorkflow Process Manager
• The Process Manager is at the heart of
  ActionWorkflow.
• It is both a workflow engine and a tool for
  managing the workflow.
• 3.Action DocRoute
• DocRoute is based upon the Process Manager and
  offers the ability to integrate document
  management and imaging applications seamlessly.
• 4.Action Metro
• Action Metro offers the opportunity to create
  workflow system which make use of the Internet.

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ActionWorkflow(cont.)

• ActionWorkflow is only available for a limited
  range of platforms.
• COSA is traditional and thorough, enabling the
  support of most routine production processes
  within administrative organizations.
• ActionWoraflow differs in many respects from
  standard workflow management system, and appears
  to be best suitd to supporting processes in which
  coordination is crucial.

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Analysis tools
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Analysis tools

• Woflan (WOrkFlow Analyzer) is a tool that
  analyzes workflow process definitions specified
  in terms of Petri nets.
• Todays workflow management systems do not verify
  the correctness of workflow process definitions.
• Therefore errors made at design time such as
  deadlocks and livelocks may remain undetected.
• To avoid these costly problems, it is important
  to verify the correctness of a workflow process
  definition before it becomes operational.

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Analysis tools (cont.)

• Woflan takes a workflow process definition
  imported from some workflow product, translates
  it into a Petri net, and tells whether or not the
  net is a sound workflow net.
• Using some standard Petri-net analysis techniques
  as well as those tailored to workflow nets, the
  tool provides diagnostic information about the
  net in case it is not a sound workflow net.

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Selecting a workflow management system

• The selection process begins with the listing of
  the requirements which the system must meet.
  Based upon these, a shortlist is then compiled.
• One way to quickly gain a good impression of a
  workflow management system is to work through a
  sample process chosen in advance.
• The sample process is representative of the
  relevant business processes.
• Once the workflow management systems on the
  shortlist have been put on trial in this way, it
  usually becomes clear which package is the best
  choice.

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Exercises

• 5.1
• 5.2(b,d)