Windows
Workflow
Foundation
Guy Burstein
Senior Consultant
Advantech – Microsoft Division
http://blogs.microsoft.co.il/blogs/bursteg
WF - Basic Concepts
Visual Studio Designer
Concepts
Workflow
Activities
Host
Components
Base Activity Library
Runtime Engine
Runtime Services
Visual Designer
Host Process
A Workflow
Activity
Windows Workflow Foundation
Base Activity Library
Workflow Runtime Engine
Runtime Services
Building a Simple Workflow
Recruitment Workflow Challenges
“Recruitment may
take several weeks
and
even months…”
“Recruiting one
applicant may be
very different
from the other…”
“What is the
status of this
applicant and
what its the next
step?”
Flexible
Long Running
& Stateful
Transparency
Long Running Processes
Recruitment
Manager
Candidate
CV
Technical
Interviewers
Manager
Persistence Service
By Default – Workflows run
without persistence
Plug in the persistence
service using code
or configuration.
Out of the Box
SqlPersistenceService
Create your custom
persistence services
Database
Workflow
Windows Workflow
Foundation
Runtime Engine
Runtime Services
Persistence Service
Long-Running Processes
Workflow (Custom) Activities
Activities are the building blocks of
workflows
The unit of execution and re-use
Out of the box Activities
get you started…
Write custom activities for
modeling advanced control flows
modeling various workflow styles
integrating with technologies
aligning with standards
Building Customs Activities
Fault Handling
Many causes for exceptions during run-time
Fault Handling used to cleanup partial and
unsuccessful work.
WF Fault Handling consists:
Fault Handlers
Transactions
Compensation
Transactions and Fault Handling
State Machine Workflows
Driven by external events
Unpredictable sequence of events
Many alternative business paths
Composed of States, Events, Actions and
Transitions
Infrastructure to query and
interact with a workflows
instance
Skip And Rework
S1
S2
S3
S4
Example: Recruitment State Machine
Waiting
For CV
On CV
Received
On Evaluated
Active
On Sent to
Customer
Waiting for
Customer
On
Approved
On Sent
to Manager
Waiting for
Manager
On
Approved
Completed
State Machine Workflow
Tracking Service
Provide consistent and reliable reporting
Past, Present and Future
Key Indicators
Auditing / Monitoring
Specify, capture, store, and query
Track workflow, activity, user events and
data
Use OOTB SqlTrackingService or a custom
tracking service
Providing Application
Transparency
Business Rules and Conditions
Added Value
Modeling Power, Approachability, Ease of
Change
Terminology
Conditions, Rules, RuleSet
Rule-Driven Activities
Rule1
Step1
Data
Rule2
IF-Else, While, Custom Activities.
PolicyActivity
Can use Rules API outside Workflow
Step2
Use Conditions
to Decide how to
Handle
Apply Policy to
Validate CV
Policy to
determine CV
Routing
Workflow Rules!
Dynamic Update
Step2
Step4
Step1
Step3
Respond to unforeseen events,
circumstances.
Apply changes to running instances:
Step5
Step6
Add / Remove activities
Change conditions (only if declarative).
Workflow Changes must be Valid
Must be validated by all activities
Dynamic Update Condition on Root Activity
Making Changes to Running
Workflow Instances
WF vs. Biztalk Server
Biztalk Server is a product for BPM and EAI.
WF is a framework for developers
Ask yourselves:
Do I have to change the message schema?
Do I have to integrate with another systems /
platforms?
Do I need the ability scale out?
Do I need monitoring and administration?
Can use both in same solution.
WF in Application Layers
Validation Rules
Page Flow
Communication
Workflows
Custom Activities
Runtime Services
Summary
More than a Drag & Drop technology
A Picture’s worth more than 1000 words…
Lets you focus on the business processes
Use Windows Workflow Today!
Resources
WF Dev. Center
http://msdn2.microsoft.com/enus/netframework/aa663328.aspx
WF Community Site
http://wf.netfx3.com
WF MSDN Forum
http://forums.microsoft.com/MSDN/ShowFo
rum.aspx?ForumID=122&SiteID=1
My Blog
http://blogs.microsoft.co.il/blogs/bursteg
Guy Burstein
Senior Consultant
Advantech – Microsoft Division
http://blogs.microsoft.co.il/blogs/bursteg