On September 25th, The Unified Modeling Language (UML) turned fifteen years old this week (Sept 25). Over the years, UML has come to play an important role in modeling modern applications. But like many modeling and code generation formats, it is not without controversy.

The joke sometimes goes that the architect and requirements people build the model and pass it on to the development team, which says ‘thanks’ and then, when the architect is gone, have a ‘model buring party’. The fact that the model seldom seems to reflect the enventual ‘build’ is especially annoying.

Before its arrival, the area was overrun by competing object methodologies. Today, UML is used to model the structure and behavior or software systems across industries. It is also the basis for many modeling tools, from companies both big and small. UML 2.0 introduce MDA – Model Driven Development – that supported code generation from UML.

But as its birthday approaches, UML faces criticism from those who say it has become too complex. Some even claim that UML is less usable today than it ever was in the past. At the same time, the merits of UML are still being extolled, while future changes to the language are discussed. The next step for UML is Version 2.5, which in ways appears intended to address some concerns. [SearchSOA.com]

http://searchsoa.techtarget.com/feature/Unified-Modeling-Language-at-Fifteen-What-a-long-strange-trip

and if you're selling IBM software

There is something of a consensus among the software engineering community regarding (1) the benefits of models and (2) the failures of UML. As should be expected, that consensus translates into fragmented modeling practices and, more generally, software engineering methodologies. Obviously there isn't much of a future for UML along that path, but the case is still open and the trend can be reversed by putting users needs back on UML driving seat.

http://caminao.wordpress.com/2012/09/17/uml-us/

To draw from Martin Fowler's wonderful bliki entries, to me UML beyond the whiteboard loses value quickly.  As a communications facilitator, UML has done a wonderful job standardizing and making portable the ability to convey systems understanding.  That's were I stop.  

I have found tools to be more limiting and alway end up failing.  Successful tools are very limited and tend to have anemic models or very mature ones.