Dear Jun, Thanks a lot for your detailed reply. Based on this, I'd like to conclude something. Kindly clarify, if anything is mis-interpreted. 1. Hope I can follow RUP as our development methodology undoubtedly. How it can be used for our product development? If we go for any certification (like CMMi) how will RUP help us to achieve this? 2. UML diagrams have to be included as part of the SRS, HLD, LLD, etc. How requirement traceability is achieved using Use-cases? 3. OOAD can be used even for Web based applications. But not commonly used. Kindly suggest me the following: 1. Forums on UML 2. Some sample case studies using UML for the better understanding Thanks once again, Sarvan AL