Re: constraints use cases/stories? [was: a first tilt at the strawman]

I did not say we needed a "new rule language"! Quite the contrary, 
and vociferously, in many mails. I merely give the example as as a 
use case of where constraints are needed as an important class of 
rules.

Now a more specific response to the technical point. OCL is used to 
express constraints across MOF compliant resources. Most web 
resources are not MOF compliant. EJB deployment descriptors (say) are 
XML. So might be project plans, quality assurance schedules, staffing 
lists - all of which constrain UML models but are out of scope for 
OCL.

Some further discussion of this point see:

C. Nentwich, W. Emmerich, A. Finkelstein and E. Ellmer, "Flexible 
Consistency Checking," ACM Transactions on Software Engineering and 
Methology, vol. 12, pp. 28-63, 2003. 
http://www.cs.ucl.ac.uk/staff/A.Finkelstein/papers/flexible.pdf


I leave the issue of whether OCL is in scope as a 'rule language' 
which we need to interoperate with as an exercise for the reader!

Anthony



>
>  >Helen and Xavier are software engineers. They wish to ensure that the
>>instances in their UML collaboration diagram correspond to valid
>>classes in their class diagram. They also want to ensure that the
>>class diagram corresponds the code base and the deployment
>>information.
>>
>>Each of these imply constraints across the information. These
>  >constraints must be checked to see if they hold.
>
>With respect to the last example: Why do you think we need a new rule
>language to express constraints on UML models given that UML includes
>the Object Constraint Language (OCL) [1]?
>
>-Evan
>Evan K. Wallace
>Manufacturing Systems Integration Division
>NIST
>
>[1] http://www.omg.org/docs/formal/03-03-31.pdf


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Anthony Finkelstein
Systemwire
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Received on Saturday, 9 July 2005 16:10:32 UTC