Thanks Kyle.
For my present project,in VB,I am going to use ActivexEXE/DCOM.So,as per yur definition,I should develop some screens,and use DCOM,to see if it is working ,and gives good performance.
Also,another question-in iterative development,will data model also be developed iteratively(ie in small chunks),since at the end of every iteration we need to do full
testing(unit/acceptance)