EmPowerTec UML and modeling blog

Hello,

if you would like to better understand the concept of UML profiles and their relation to the Object Constraint Language (OCL) I would recommend to read the nice paper OCL-based Validation of a Railway Domain Profile by Kirsten Berkenkötter.

Usually, OCL is propagated as a means to make UML models more precise, i.e. “better”, by adding information to the model that cannot be expressed with diagrams.

The usage of OCL in UML profiles is the other major application of the OCL. There it is used – along with stereotypes – to create a domain specific subset of the UML that is better suited for a given domain than just plain UML. Usually, a UML stereotype also defines a domain specific graphical presentation for the stereotyped element.

If you are familiar with the world of software modeling you are probably aware that currently two major schools of thought are contending for dominance. There are the proponents of Domain Specific Modeling Languages (DSL) who claim that a dedicated modeling language must be created for a specific application domain to allow effective modeling. And then there are the proponents of UML who claim that the UML provides a standardized, well defined and widely known modeling language which can of course be tailored to a specific domain (using profiles). Unfortunately, most of the people who make public statements concerning these contending approaches are biased, because they work for a tool vendor. For example, people working for IBM Rational will advocate the usage of UML, and people working for Metacase will propagate the DSL approach. Since this is a complicated topic I’m afraid that the only way to find an answer to the question “which is the best approach for my specific project?” is to make a careful evaluation and maybe a pilot project.

Best regards,
Andreas

Technorati Tags: UML, DSL, OCL

Hello,

since 2008-04-01 I’m an OCUP fundamental now. Compared to various Microsoft exams I have taken more than 10 years ago this certification was pretty hard, for three reasons:

• The exam mainly checks the UML specification itself and not whether you can create good models (that is, using UML for describing the results of analysis and design work). This means, even if you are a experienced applicant of UML this knowledge won’t be of much use in the exam. In the standard Microsoft or Sun certification exams it is a significant advantage if you have been exposed to the relevant technologies in your work before.
• The checked content is very abstract and rich in detail. The UML specification is about 1000 pages thick and the fundamental certification covers about 1/3.
• There are no practice exams available, e.g. from Transcender or MesaureUp like for the more standard certifications. These practice exams are a very effective exam preparation.
• The preparation material I have used was written in German, but the exam was in English.

But I’m absolutely confident that the knowledge I have acquired during the preparation will help me to create better products for EmPowerTec. And it sure was a good feeling when I received my result after the test

Best regards,
Andreas

Technorati Tags: UML, certification, OCUP