brian@edat.UUCP (brian douglass personal account) (05/07/91)
I'm not sure if this is the right group or not, but it doesn't seem any other group was more approrpriate to ask question about Systems Development LifeCycle (SDLC) approaches and Structured Systems Analysis. Here goes. When I do an analysis I use traditional Yourdon DFD tied into Chen ERDs. I am very happy with this. A new theory I am learning places sequence numbers on each data flow to present the sequence of events. By following the numbers you can see the system change from state to state. The instructor is saying that Yourdon DFDs are on their way out being replaced by this Enviromental Model (EM). Is this true? In this system, their is a tremendous fixation on physical rather than logical. The reasoning being Management relates better to a physical model where they can trace the steps through versus a logical model (like a Yourdon DFD) where there is no sequence of events (I contend that state-less machines are the better approach with the arrival of data at a process serving as a trigger for a sequence of events within the process defined through Structured English). Is the world of SSA and SDLC going to modeling through state transition? Lastly, they use something called Programming Logic Diagrams (PLDs) to document program flow. It is sort of like an outline, but uses brackets to show program development. To me, this method again can become overly physical if the analyst is not careful. |--get supplies | | make PB&J --|--spread supplies Sandwich | | |--put bread together The teacher claims this type of diagramming is replacing DFDs also. There is no ER modeling, and they have I/O modeling (this goes to this disk, and to this printer). Is anyone using this kind of technique or heard of it? What are most people using? Thanks in advance. (E-mail and I'll summarize) Brian Douglass Voice: 702-361-1510 X311 Electronic Data Technologies FAX #: 702-361-2545 1085 Palms Airport Drive brian@edat.uucp Las Vegas, NV 89119-3715