Hard Fact: MDA Works!!!

Just de-emphasize the "platform independence" issue, forget about the UML and bin the PSM and any reverse engineering you had in mind.

Industrial experiences of this kind of "MDA" show improvements in productivity and quality with a FACTOR of between 5 and 10 times compared to UML-based MDA implementations.....ehr....hypothetical UML-based implementations of MDA that is :)

Defining DSLs, Best Practices

Juha-Pekka is writing a series of articles on domain-specific modeling for DevX.com. With 15(!) years of experience in this area I suppose he definitely is an authority when it comes to DSLs, more correctly referred to as DSM languages. His second in the series deals with defining DSLs. Over the years involving many workshops, pilot projects and close co-operation with customers he has identified a number of best practices for teams in order to come to good DSM languages, as not every DSL is neccesarily a good one!

Defining DSLs based on RUP

Evgeny Rahman and Jarrod Bellmore from the Worcester Polytechnic Institute have investigated a method for defining DSLs based on the Rational Unified Process. Hats off for their thesis work. While I will not argue the suitability of RUP for defining DSL's (I can imagine a whole future battle between DSL-RUP aficionado's contra Agile DSL guerilla's), I do have much respect for the topic choice they decided on for their thesis work. Defining DSL's certainly will be a key issue. Now that the technology is there and more vendors announcing support for DSM, the next obstacle that those wanting to adopt DSM will be faced with, will be "Ehrrrrrr.....so how do we actually define our own modeling language"?

Next-generation DSM tools may even offer support for various DSL definition processes, including the creation of all documentation for decision making processes during the DSL definition and maintenance. Remember that like developers today, language designers will change jobs in the future and for those that replace them good documentation about the choices made by their predecessors about the DSLs in use and their evolution over time, will help in making future decisions on where to go with the languages in use.

Interview with Steven Kelly

Codegeneration.net has published an excellent interview with MetaCase CTO Steven Kelly about DSM, MDA, Software Factories and developing a meta-CASE, DSL tool like MetaEdit+.

You already speak DSL!

Often a first reaction of prospects - when confronted with domain-specific modeling - is: "So we have to define and learn a whole new language?".

Actually, this is not correct.

I dare say that virtually every developer already speaks DSL! When discussing about the problem domain of the software under development, each development team has their own jargon in which they speak about the software or system. No one speaks about the software in Java, C or, mind you, in Cobol or Assembler. Developers all speak about their software in a language that uses terms and rules from the problem domain he or she works in. Usually, the expert developer speaks that language best and DSM gives him (or her) the means to make each "less fluent" developer "speak" that language fluently.

The idea of course: Give the expert a tool to efficiently create modeling tool support for his/her DSM language and provide this language to the rest of the developers.

Unlike with UML, with DSM developers do not have to learn a new language, that, all things considered, is never really optimal to "discuss" about the software. Instead, with DSM the expert provides them with the language they already know so that "discussing" about the software in your verbal DSL comes closer to developing the software in your visual DSL.