1. Introduction to Windows Workflow Foundation (WF)
Keith Elder
Microsoft MVP
Blog:
Quicken Loans –

2. Agenda Hello World in Workflow What is Workflow? Architecture
Understanding the Runtime
WF Extensibility
Rules Engine
Scenarios for WF
Versioning
Hosting
WF in a SOA

3. DEMO HELLO WORLD

4. What is Workflow?
The workflow framework and tools for Microsoft products and partner/customer ecosystem
Single workflow technology for Microsoft® Windows®
A framework for building workflow, not an application or server
Make declarative workflow a mainstream development paradigm
At the end of the day workflow is a new namespace and supporting APIs developers can use to declaratively express business logic and long running processes.
Single workflow technology for Microsoft® Windows®
Base for Microsoft products and independent software vendor (ISV)/customer solutions
One technology for human and system workflow scenarios
A framework for building workflow into applications
A framework to build on - not an application or server
Exposed to developers via WinFX®
Brings workflow to mainstream Microsoft® .NET development
Transform workflow from niche to mainstream paradigm
Build strong partner and solution ecosystem

5. Architecture A Workflow An Activity Windows Workflow Foundation
Host Process
Windows
Workflow Foundation
Runtime Engine
A Workflow
An Activity
Runtime Services
Base Activity Library
Custom Activity Library
Visual Designer
Key Concepts
Workflows are a set of Activities
Workflows run within a Host Process: any application or server
Developers can build their own Custom Activity Libraries
Components
Base Activity Library: Out-of-box activities and base for custom activities
Runtime Engine: Workflow execution and state management
Runtime Services: Hosting flexibility and communication
Visual Designer: Graphical and code-based construction

6. Understanding the Runtime
Host Application
App Domain
Runtime
Services
Out of Box Services are provided that support SQL Server 2000 & 2005
Services
PersistenceService stores and retrieves instance state.
SQL
PersistenceService
TrackingService
TrackingService manages profiles and stores tracked information.
SchedulerService
TransactionService
Common resource services for managing threading, timers and creating transactions

7. Activites: An Extensible Approach
Vertical-specific activities and workflows
Best-practice intellectual property (IP) and knowledge
Domain-Specific Workflow Packages
Compliance
RosettaNet
CRM
IT Mgmt
Base Activity
Library
Custom Activity Libraries
Compose
activities
Extend
activity
Author new
activity
Out-of-Box Activities
Theme you’re going to see throughout WF
Activities are completely extensible. All of the activities that ship in WF are built the same way, so you have access to all of that extensibility, designers, look and feel, etc
OOB activities, workflow types,
base types
General-purpose
Activity libraries
define workflow
constructs
Create/Extend/ Compose activities
App-specific building blocks
First-class citizens

8. WF Extensibility Designer Rehosting

9. DEMO CUSTOM ACTIVITIES

10. Workflow Rules Conditions on activities Policy activity
12/9/ :11 AM
Workflow Rules
Conditions on activities
If-Else
While
Replicator
Conditioned Activity Group (CAG)
<Your custom activity>
Policy activity
Contains and executes a RuleSet
RuleSet execution provides priority-based, forward-chaining semantics
Rules can be used outside workflow
© 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

11. Forward Chaining RuleSet Execution Sequence Amount = $25 Total = $80
Rule 1 (P0)
If Total > $50 & < $100
Then Discount = 10%
Rule 2 (P0)
If Total >= $100
Then Discount = 15%
Rule 3 (P0)
If Amount > $0
Then Total = Total + Amount
Amount = $25
Total = $80
Discount
$105
= 10%
15%

12. 12/9/ :11 AM
Policy Overview
Policy activity references a RuleSet in the workflow.rules file
RuleSet class contains a collection of Rules
Rules are If-Then-Else expressions that evaluate and operate on workflow members
© 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

13. CAG - Overview Child activity executes CAG executes
12/9/ :11 AM
CAG - Overview
Child activities
Child activity executes
When(Condition1)
CAG executes
Until(Condition2)
Default execution is a parallel
When
Executes activity once
Until
“All children quiescent”
Executing children complete and all When conditions == false
Conceptually, an
activity executes:
IF When && !(Until)
© 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

14. DEMO RULES ENGINE

15. Versioning in WF – Where?
Workflow
Activity
Tracking Profile
Rules
Host and runtime services
Exposed as a web service
The highly extensible design of the runtime, activities and services enable opportunities for versioning in a number of different places.

16. Workflow Versioning Compiled Declarative
Standard .NET versioning story
Strong Names, GAC, etc.
What I’m not going to dive into the details of
Declarative
This is what we call XAML-only workflows
Versioning here takes place in the host, when deciding what XAML to grab
But wait, my workflows are already running!
DynamicUpdate API address how to change these
Declarative
There’s going to be some repository you will need to enable an effective declarative approach (otherwise you’re loading a string, which is kind of boring)
In this repository, you are going to need to track some kind of version (or maybe you only have the most recent available in a text file on a file share somewhere)
This text file outlines the arrangement of your activities, and their individual configuration, so if you introduce a new activity, you need to make sure that assembly is available to the host when it comes time to initialize that activity.
Also, have the XAML v. XOML talk

17. Cluster of Workflow Runtimes accessing the same persistence store
Scaling?
Cluster of Workflow Runtimes accessing the same persistence store
Host* 1
Host 2
Host 3
Host N
Workflow Runtime 1
Workflow Runtime 2
Workflow Runtime 3
Workflow Runtime N
SQL
Persistence
Service
SQL
Persistence
Service
SQL
Persistence
Service
SQL
Persistence
Service
The persistence service will take care of ensuring that an instance doesn’t get spun up on multple hosts?
But I want a sophisticated app provisioning capabilty built off the same persitence store…. Write your own persistence service!
The out-of-box SQL Workflow Persistence Service allows multiple workflow runtimes to use the same persistence store
Locks workflow instances when used by workflow runtime
Lock timeout interval
Avoids locking of workflow instances by serially retrieving them when service is initiated
Delivers all timer events when service is initiated
SQL
* The host could be IIS

18. WF in a SOA
WF Orchestrating Services
WF As Service Implementation

19. DEMO Calling Workflows via services

20. Introduction to Windows Workflow Foundation (WF)
Keith Elder
Microsoft MVP
Blog:
Quicken Loans –