David Marca presented at today’s meeting of my local section of IEEE on the topic of modelling systems. David’s focus is not on a modelling something like a filter or a channel but rather the context in which an enterprise operates.
If the team doing the work and the customer both understands the problem being addressed on a project, Agile Methods can handle the specification. Usability Engineering is when someone on the team works closely with the customer to get feedback.
More complicated problems or problems that are new to the team and the customer can be modeled with a Universal Modelling Language (UML). SADT/IDEF0 is one such method.
My understanding is SADT/IDF0 is a model of an asychronous state machine. While it’s in a given state, the system acts as a time-invariant continuous-time system. Every time the “state” changes, the transfer function of the time-invariant system changes.
I would love to hear feedback on whether my DSP-ish understanding is right.