Web Services Strategies
Beyond the technology, IT strategies for implementation of Web services by Doug Kaye.
Weekend Reading. Writing a new chapter, Transactions, Business Processes and Workflow, I caught up on related documents in the pile on my desk:
- Business Processes: Understanding BPEL4WS by Sanjiva Weerawarana and Francisco (Paco) Curbera, both of IBM, is a good introduction.
- Automating Business Processes and Transactions in Web Services by James Snell, also of IBM, covers the broader spectrum of transactions in general, along with WS-Coordination and WS-Transaction in addition to BPEL4WS.
- In A Novel Approach for Modeling Business Process Definitions (a 16-page .doc file) Jean-Jacques Dubray of Eigner presents the BPMI perspective on extracting process-oriented logic from applications. (You can't automate a multi-party workflow if the business logic is trapped inside the apps.) He breaks down four levels of business processes including enterprise processes, executable processes, business-process collaborations and individual tasks.
Posted Monday, September 02, 2002 2:56:57 PM
More on BPM and Workflow. Last week I posted a graphic portraying the latest protocol-stack developments in web-services transactions, workflow and business-process modelling and automation. As expected, I received some excellent comments from readers.
Jean-Jacques Dubray (chief architect at Eigner, author of Professional ebXML Foundations, and a co-creator of ebPML.org) writes:
I often get asked the questions: where is this whole Business Process Modeling (BPM) thing going? what is it good for? why people think it should be based on open technologies? Here is my one page answer. In one sentence I would say that the goal is that infrastructure providers such as Microsoft and IBM are working towards delivering an application model which will enable a complete separation of the process-oriented business logic from the model and presentation oriented business logic.
Dave Wright (Microsoft .NET Architecture Evangelist, who knows a lot more than that title might suggest) points out:
- BTP and WSCI both compare against WS-Transaction and WS-Coordination; that is together they compare, but separately the don’t map as cleanly.
- WS-Transaction defines 2 "transaction types", one for synchronous ACID transactions, one for "business activities." BTP compares (mostly) to the former, and WSCI (mostly) to the latter.
- In understanding the difference between a "business activity" as defined by WS-Transaction and a business process as specified in BPEL4WS, understand that BPEL4WS (and BPML) are design to specify the "internals" of a workflow, and WS-Transaction and WSCI are designed to specify the "public behavior" of workflow endpoints as they cohere in larger, cross-organizational business processes. So WS-Transaction and WSCI are all about defining the distributed eventing and notification model that is responsible for flow control as it passes across boundaries that are separately controlled by processing monitors that would be executing BPEL4WS or BPML schedules.
- WS-Coordination defines a lifecycle model for instantiating and executing distributed transactions at runtime: creating a shared transaction context, registering participants within the context and helping participants map themselves to various WS-Transaction protocols at various stages.
Posted Monday, September 02, 2002 2:04:06 PM