every one must have seen many OO designers saying that dont think of implementation at design time. On the other hand at the same time we see people talking about the design patterns which come from common best practices (obviously implementation). Should one think of implementation at Object Oriented design time or not? Or should we stuck at Never ever think of implementation at analysis/design time. Regards, Khurram Mahmood.
I think one of the biggest common problems is a confusion between "analysis" and "design". Analysis can and should often be done independent of implementation. Analysis is about finding the problem which needs to be solved or the benefits which need to be provided, and says nothing about how it should be implemented. Design is about taking the results of analysis (be they "requirements", "user stories", process models or whatever) and deciding how to implement them. I find it hard to understand how this could ever be done without considering implementation. Can you clarify why you chose to lump these two processes together as "analysis/design time" in your question ?
yeah you are right The two processes (i.e. analysis and design) are different from each other asnd people often get confused when talking about the two. In the analysis we identify use cases, concepts create conceptual model etc. And in the design is about how to implement these concepts and shape them into Objects. But my question is that what we do in the design pattern we make use of our common practices so why is it said that do not think of implementation at the design time? The pair analysis/design that I used is due to the fact that we at times can not put a line of demarkation between the two (Except for the old definition that analysis replies "What" type of questions and design does the same for "How " type of the queries.
Originally posted by Khurram Zaman: ...my question is that what we do in the design pattern we make use of our common practices so why is it said that do not think of implementation at the design time?
Can you cite a specific source of this advice? Who said it and in what context?