UML Design for ISA95
Posted by hatim
My first actual task for the ERP application is to finalize the design of Graphical Modeler. This task involves understanding the complete user requirements, making their UML diagrams and documenting use cases. This particular exercise brought me back to learn UML after a long time. Last time I touched UML in detail was in 2002 in my OOP course. So I got a book called () th help me out in this.
UML is some thing which is to be taken lightly. You cannot draw all diagrams for a particular problem and you cannot nail the design in one go. It's a process which is very iterative. The end product is a design which is re-factored over many times from the original design. It is good to keep one's design simple, but I think this statement is overstated as well. Elegant designs are some times complex (for example there are complex systems which keep us alive while we are flying, and did i mention complex). Any who ISA-95 has 4 different basic models on top of which other models are built (namely personnel , equipment, material, process-segment).
We first started with most simple of them called the Personnel Model. As from a programmer point of view (and that too of an OO language) the crown jewel of all the UML design activity is a class diagram. Fortunately (or unfortunately) class diagrams are already suggested in the standard. In normal circumstances we reach to the class diagram through a methodological way, in which we happen to generate all other sorts of diagrams. But since we already had the class diagram the process becomes a bit fuzzy (since all other diagrams now have to suite the class diagram). But all in all I got to have 3 weeks of design only :)
Update: it seems that design phase will go on for some more period of time as well.
