Rules of Thumb for Creating XML Vocabularies for WorkflowApplications [

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

I changed the subject line on this email thread to reflect its tighter focus.

I've incorporated the latest comments. Please let me know of any changes you recommend. /Roger


DEFINITION

The list below contains guidelines for creating XML vocabularies for workflow applications. In XML-based workflow applications the XML documents are routed, and may be modified at various stops along the route.


RULES OF THUMB FOR CREATING XML VOCABULARIES FOR WORKFLOW APPLICATIONS

1. An XML vocabulary does not exist in a vacuum. It exists for some purpose or purposes.

2. An XML vocabulary must support the data needs of both the data producers and the data consumers.

3. An XML vocabulary that is too generic will fail. Focus the XML vocabulary to a specific purpose or (small) set of purposes.

4. If there is markup (data) needed by the consumers but not the producers then make it optional. Thus the producers can omit the optional markup while the receivers can add it.

5. Design flexibility and extensibility into the XML vocabulary, but do not try to predict the future.

6. Modularize the XML vocabulary. Create the XML vocabulary as an assembly of building blocks ("data components").  

7. Split out markup (data) that is optional and specific to the consumers. One technique, for example, is for the consumer to add the data that is specific to him in an envelope that wraps the producer's data. The envelope topology is one approach to component-based design; many others are possible and should be explored.