Wednesday, September 24, 2008 – The Reader, a harried project lead, wishes he could get his development under control.
This Episode introduces the absolute minimum useful Use Case Diagram. If it seems simple, it is. I want to show you that “speaking” UML is easy, if you start simple and grow. I don’t want to overpromise. UML isn’t a cure-all. It’s just a tool for communication. Let me repeat: It’s all about communication.
And if this diagram seems trivial, well, keep reading! We’ll get more complex.
And if you don’t understand the porkpie hat and Swingin’ on a Star, you should go rent Bruce Willis’s masterpiece, Hudson Hawk. You’ll love me for it, or you’ll hate me; but you won’t easily forget it.
UML is not a process. It can be used in any process, from ad hoc to Agile to Orchestrated Development.
UML is not a tool. You don’t need Microsoft Word to speak, read, and write English. You don’t need any tool to “speak” UML. (But a good tool can make it easier!)
UML is not like the Oxford English Dictionary. It’s not formal, unless you need to be formal.
UML is a diagram-based language for building Models.
UML is not about code. It’s not even about software design. It’s about models of systems, where…
- System = Structure + Behavior + Purpose.
- Structure is expressed in Class Diagrams, Component Diagrams, Deployment Diagrams, and more.
- Behavior is expressed in Activity Diagrams, State Diagrams, Sequence Diagrams, Communication Diagrams, and more.
- Purpose is expressed in Use Case Diagrams, Activity Diagrams, State Diagrams, and more.
UML is a diagram-based language for building models using a Unified notation.
UML incorporates best of breed from prior notations.
Elements in one diagram can appear in other diagrams and add more detail.
One kind of diagram can add detail to another kind of diagram if you choose to use it that way.
These messages bear repeating. Expect me to repeat them.