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UML Fever
CowboyRobot writes "Queue has a couple of articles about UML:
Death by UML Fever by Boeing software architect Alex Bell
describes the problems that can result from over-reliance on modeling tools, with lighthearted lessons for the software development process in general and numerous illuminating quotations, such as: "Good judgment comes from experience. Experience comes from bad judgment. - Jim Horning."
Then, one of the developers of UML, Grady Booch of IBM, follows with The Fever is Real, in which he explains the motivations for creating the language, how it's used today, and where he expects it to go soon."
Who uses UML? The designers or the programmers?
I should imagine the designers wouldn't be very good at it, and I should imagine that programmers would have better ways to express themselves.
Actually a good designer probably has some experience coding. As to who uses it? Well ideally the designer or project leader should author it and the programmers should be able to read and understand it, so both parties technically use it.
Pretty widgets? What pretty widgets?
Contrary to his opinion, the one he never ceases to state, over and over again, there were modelling systems before he 'invented' them all. There have always been ways to annotate a software design with clarity and there always will be.
Has anyone ever worked with anyone who is totally focussed on the UML? We've had to get rid of them as they don't contribute anything except endless debates and meetings that are way too long. Sometimes you have to deliver stuff. I bet he missed that bit while he was writing papers about how revolutionary he is.
Things are changing... Look at the Eclipse UML2 project (http://www.eclipse.org/uml2/).
There is an OMG standard for the serialization of UML model: XMI. And there is an OMG guideline on transforming the models: MDA.
Now, if only all tools adhered to the XMI standard as their main storage method... Although most can currently output some variant of XMI (although there's just too many right now).
But then again, this is all about tools. There is nothing that would prevent you from using the UML notation on a whiteboard...
Paul Harmon and I wrote a book on UML about 5 years ago.
At first, I thought that UML was a godsend because it did away with 12+ different modeling languages.
Still, for most of my work, schedules are very tight and my customers usually want to spend as little money on development as possible, so I find myself only using what I consider to be the highest value diagram types: use cases, very general class diagrams, and sequence diagrams.
-Mark
Rammed earth walls will survive much stronger earthquakes than frame construction
15,000 recently dead Iranians dispute that claim.
Granted, you can build earthworks that are stable with modern technology, using metal and concrete reinforcements and a better knowledge of materials science.
And one day, software engineers might be able to write a pile of C++ that doesn't fall down when pushed.
I have a positive modifier on Troll. When I mod someone Troll their karma should go UP!
Well, I'm one of the authors of the UML 2.0 specification, so karma be damned. Here's a totally biased response.
1. UML enables communication on design, architecture that everybody can contribute too. The standard notation and concepts in UML 1.x enabled a foundation for communicating in a team about aspects of software that are not easily gleaned from the code.
I think this in itself makes standardization worth it. Also, it's not a secret language of architects. You read the same books they do.
2. You don't have to have all in one place. The nature of modeling allows models to be developed across different diagrams. UML 1.x is incomplete in this area, UML 2.0 does better. Pushing this notion could lead to some to some interesting places, one could be AOP without requiring AOP code.
3. Some changes are easier in UML. Tools don't do a good job of this, but I find it much easier to change object hierarchies and relationships in UML than in code. Imagine extending this to other areas besides the static layout of classes.
4. Metamodeling. The problem with UML and it's tools right now is the complete lack of metamodel extensibility mechanisms. It's like XML, but you can only use a fixed set of schemas.
This could be a real rat trap, but on the other hand, it could very cool. For example, imagine extending the base class metamodel to add what your project needs for persistence, integrity and object communication, and instead of writing code for every class to enable your special features, you use a model tool and templates to automate most of the process for every class.
5. Little Languages that everybody can use. If metamodel holds promise, it is basis for providing Domain-Specific Modeling Languages that take advantage of common metamodel concepts and visual syntax to reduce the learning and usage curve for every language. Having standards in this area help ensure interoperability and lack of lock in.
Oddly, Microsoft is the only vendor right nowthat really seems to be taking on the notion of metamodeling and DSMLs. I expect IBM and others in Eclipse to do the same around the EMF.
6. Modeling could be a complementary abstraction to programming languages. With some exceptions, we rely on code to produce systems. In some areas, models can often provide additional information that is not "immediately clear" in the code, and can automate the generation of that code.
An excellent example is E/R modeling. I would argue that E/R modeling serves as an good tool for designing relational databases, and shows things about the database that may not be clear from the set of DDL statements.
Now, imagine having the ability to create a whole set of these models that all carry a common infrastructure and tool set. Your DB modeling tools is your XML modeling tool is your OO modeling tool is your Workflow modeling tool, and so on.
The problem is that I view UML as "modeling middleware". I don't see it as just a notation, but I see it as a core infrastructure to base modeling tools on. This probably because I worked on the metamodel. In other words, I've spent too much time inside UML that I see the outside much differently.
Granted, most tools make it seem that UML is pretty (expensive too) pictures. But, hopefully, with UML 2.0, people will understand the real promise of UML and modeling. I think it goes beyond the surface syntax.
Now modeling is not UML. In fact, if Microsoft really pushes forward with Whitehorse, they may create the de-facto modeling standard.
The UML community becomes much more aggresive about providing metamodeling capabilities. Also, XMI needs to improve big time. Also, the OMG and UML would be well served by reaching out to MS and staying in tune with where they are headed, so they don't get caught totally off-guard. There is hope, I think MS has does some good work for the W3C (and some bad work, of course).