Article: Implementing Manual Activities in Windows Workflow

by Stefan Tilkov on May 06, 2008 |

In a new InfoQ article, SOA editor Boris Lublinsky explains how to handle human activities in a workflow managed by Windows workflow foundation (WF).

While Windows workflow is an excellent framework for implementing business processes, it lacks direct support for human activities. Several approaches to solving this problem exist, but they are not generic enough for general usage. Boris shows a completely generic implementation of human activities in WF, using a work queue manager as a decoupling layer between workflow engine and human activity execution:

This is a centralized service keeping track of all tasks for all of the users of the system. Any workflow (or a service/application containing workflow), which requires a human activity, invokes a custom workflow activity, which submits the request to the work queue manager persisting them and allowing other components of the system to work with these requests. By doing this a work queue manager is becoming a decoupling layer between workflow engine and human activity execution, thus providing support for the cases where user is not present in the system during workflow execution. Also by being a centralized service a work queue manager allows to combine all of the tasks for a given user, regardless of the process that they have initiated from. Because different user tasks can require different input information and can produce different outputs, communications between workflow and human activity is XML in and XML out, which allows processing any possible request and response generically.

Boris elaborates on the internals of the whole system, highlighting important design decisions and the rationale behind them. Check out the full article for more information.

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Community comments

Great article! by Julien Jacobs Posted

Source Code by Tobias Hertkorn Posted

Superb! by Haris Sheik Posted

It's the Humans Stupid! by John Reynolds Posted

Very Helpful! by Derrick Bell Posted

Excellent Article by Gustavo Marotta Posted

Great article by Shirvan Noormohammadifar Posted

Would like to now more.. by Sharad Patel Posted

Great article! by ttotpt ttotpt Posted

Great article! by Julien Jacobs

Thank you for this great "real-life" article!

We are working on a project involving workflows and lots of human activities, and this article re-enforces what we started to put in place.

Is there any plan for publishing the source code?

Source Code by Tobias Hertkorn

Hi,

thank you for this excellent article. I really enjoyed it.

Like julien I would be very interested in the source code as well. Could we have some feedback if a release of the source is possible or if we have to implement it ourself.

Tobi

Superb! by Haris Sheik

I really enjoyed this article. Like other two commenters I would like to see the code.

It's the Humans Stupid! by John Reynolds

Great article... But isn't it strange that Human Powered Services were an afterthought?

Very Helpful! by Derrick Bell

Thank you for this article. We have project underway that has a lot of human interaction. Of course looking at source code would be nice.

Excellent Article by Gustavo Marotta

Really it's a excellent article. It solve my questions about human activities in an workflow. If is possible, I like to see the code too.

Great article by Shirvan Noormohammadifar

It helps me so much in working with human activities.
It will be helpful to see the source code for this if possible.
Tanx

Would like to now more.. by Sharad Patel

about this if it is going to be a commercial/open source product. If there is source code available I would like to know from where. Also, I would like to know how far this architecture would lend itself to being used by 'business' users - e.g. the workflow designer is hosted in a custom tool that works on a code-free model.

Many thanks,
Sharad

Great article! by ttotpt ttotpt

Is there any plan for publishing the source code?

Thanks.