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Think about your design even if you don't use full UML

Archive - Originally posted on "The Horse's Mouth" - 2006-03-24 07:06:15 - Graham Ellis

Even if you don't feel that your project is big enough to get involved with formal design methods, many of the lessons of UML and some informal design diagrams can help you get a clear view of what you're going to be doing be for you start, and can help you come up a good, thought out and reliable plan before you waste a lot of time writing experimental code up a blind alley. No need to use posh symbols on your diagrams - just a few boxes will do! Try:

1. A use case diagram, showing the major data elements, and which of your user communities supplies, updates and reads which elements

2. Object diagrams, showing the various components of each of your data types and what it does

3. Class diagrams, showing how your various classes inherit from each other and at what level each of the methods should be written

4. A Deployment diagram, showing where the various component are kept - not only the live components, but the backups, source code and the whole system including the older versions and version control

5. Sequence diagram showing how transactions go through the system with each element picking up and passing data to and from the others

6. State diagram, showing the state of object types (including, in web use the state of each uses' session object). I can't believe I left this one so late to mention!

7. Procedural diagrams - a.k.a. flow charts - showing how the logic goes together.

Even if you don't draw these out on paper for each project, it's no bad thing to think through each of the 7 aspects as you work out what you're going to do - a few minutes of consideration of the big picture reaps huge efficiency rewards as you put together your application or suite.

You can download a .pdf file from our open training notes site that shows you examples of each of these diagrams - just follow the "links under _Object Orientation - design techniques.