Enterprise Integration: Workflow

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Enterprise Integration Workflow

• B.Ramamurthy
• Chapter 7

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Integration and Workflow

• Data integration capturing the data from various
  sources and dispensing them appropriately for
  consumption by application and human users.
• Application integration connecting the various
  applications so that collaborate to accomplish
  the enterprise-level tasks efficiently,
  consistently and without redundancy.
• Workflow Provides the automation of business
  processes to coordinate the activities of people
  and applications, at all levels.
• Many workflow products are available in the
  market. (You will typically be a user of one. If
  you are working for workflow company that makes
  these products you will design and build one.)

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Workflow Topics

• General Workflow Model
• Processes in workflow
• Process design considerations
• Integration elements
• Assessing scalability
• Product requirements
• Standards (OMGs Workflow management Coalition
  (WfMC)

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The Model
Process A Definition
Requester
Process A instance
Process Manager
Process B instance
Resource Assignment Facilities
Personal worklist
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Workflow Management

• Definition of processes, ex login process, order
  process, purchase process, shipping process,
  approval process.
• Process definition is installed for runtime
  execution.
• Requester of processor provides values to the
  variables of the process, and parameters for
  execution. (ex completion date)
• When the process code is executed, an instance of
  the process is created. It performs the component
  activities.
• Activities perform a variety of operations.
• Operations may request resources and interaction
  of people. (ex approval, printer for printing)

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Process Deign Consideration

• Process scope
• Process closure
• Process state versus subject matter (context)
• User roles and security
• Accountability and control
• Process back-out
• Long-running transactions
• Ancillary actions (Ex exceptions)

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Design consideration (contd)

• Process is closed loop
• Scope should be limited to the BSD
• Activities depend on the context
• Number of different people may be involved.
• Roles relate to the manner in which each user
  participates in the process and users authority
  in the process of the context.
• See the diagram given next

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User Roles
Process Defn
Requester
Responsible Party
Process Instance
Activity instance
Observer
Reviewer
Work product
Performer
Subject
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Integration Elements

• Process initiation (by programmed request, by a
  user, by an event)
• Workflow context (standards use XML)
• Application adapters
• Event detection
• Asynchronous process invocation
• Shared work products
• Security

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Workflow context

• Expressed as name-value pair
• OMGs workflow standard recommends XML
• XML features
• Provides complex parameters in a well defined
  structure
• The structures can be accessed and managed with
  well-defined operations
• XML document type definition (DTD) can define the
  content of the structure for editing.
• The same structure can be used to create
  associated user displays using XSLT.

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Accessing Scalability

• Process definitions (may spawn many other
  supporting processes)
• Active processes (use of activate /passivate)
• Number of users (activate/passivate)
• Threading model
• Execution distribution model (Ex multiple j2ee
  servers connected through a queue)
• Workload balancing (multiple beans in a container
  and their management for efficient operation)

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Product Requirements

• Process definition elements
• Process definition tools
• Workflow execution infrastructure
• Ad hoc changes
• Runtime user interface
• Compute environment
• Security
• Analysis tools