UML -- Is it still a popular method for markup/pre development /visualization of software?_问答_开发者

In my object oriented programming class, we learned some of the main concepts of UML and I was just wondering if UML is common in real world situations or are there开发者_开发知识库 more popular methods.

There are certainly organizations that rely on UML, including a few that may expect you to answer OO design questions with UML in an interview. Plus, documentation tools like Doxygen generate UML-like diagrams to describe a class hierarchy.

Beyond that though, most groups I've worked with in academia or industry don't really use it. If you want an explanation of why, read "Death by UML Fever".

Generally agree with @chrisaycock. Would add a couple of things:

You should distinguish using UML for specification versus documentation. At the peak of its hype curve, UML was touted as the former. So development processes mandated modelling in UML before moving into code. That use has diminished greatly (although there are still pockets using executable uml, notably in real-time/embedded environments).

As a documentation tool, UML is still popular. UML class diagrams, for example, can convey the structure of a module in a way that is much more revealing and intuitive than linear code can ever be. Similarly sequence- or activity diagrams are very useful for understanding flow of control for an action that transcends a number of classes.

In the documentation context UML diagrams are increasingly being generated automatically rather than being manually created, e.g. from doxygen (as @chrisaycock mentions).

However it's also still useful for sketching out designs ahead of development e.g. on a whiteboard.

hth.

I once attended a Q&A session on UML and MDA in embedded systems where the panel included authors Bruce Powell Douglass and Steven Mellor. Having previously studied and worked on RT-SSADM projects and the Ward-Mellor methodology, I challenged Stephen Mellor on why a new way of software design comes along every 10 years before practitioners have hardly gotten to grips or truly understood the last one. He responded rather too honestly perhaps with "this way I sell more books"!

To some extent therefore I suggest that the hype surrounding any particular notation or methodology is driven primarily by CASE tool vendors and publishing houses; often the authors are also employed by the tool vendors and have titles like "Chief Evangelist".

That is not to say that these tools have no value; we should all be wary of such marketing, but on the other hand we also need to communicate our ideas and designs in an unambiguous and clear manner, and using a defined notation however inelegant, will always be better than some ad-hoc "sticks and boxes" notation that has no definitive semantics. Given that need for communication, UML (and derivatives such as SysML) is currently the most widely accepted and used notation, and currently enjoys the widest tool support. It differs from much that has gone before by being defined as a standard agreed by multiple parties rather the work on a single author or CASE tool vendor, so it is likely to develop rather than disappear.

I think the article, linked by @chrisaycock, could also have corollaries e.g., "Death by Agile Fever", "Death by CMM Fever", "Death by RT-SSADM Fever", ... ;-)

As @sfinnie stated, it really depends upon the usage, but UML by itself is nothing more than a notation. In order to be really useful, you need to follow some development method. @Clifford's post not withstanding, I'd recommend a mature method. Executable UML started as Shlaer-Mellor and has been in use for 19+ years. Douglass' method (not called ROPES anymore, but ???) has been around for 11 years. The Unified Process is based on Booch, OMT, and OOSE methods, so it can be considered 19+ years old as well. Of course you might find some other UML or non-UML development method that better fits your needs.