Unit 2
- 1. Software Requirements analysis Software requirements:-A condition of capability needed by a user to solve a problem or achieve an objective. SRS :- That describes what the proposed software should do without describing how the software will do it.
- 2. Need for SRS Three major parties interested in a new system: The client The developer The end users. An SRS establishes the basis for agreement between the client and the supplier on what the software product will do. An SRS provides a reference for validation of the final product.
- 3. Characteristics of an SRS 1. Correct 2. Complete 3. Unambiguous 4. Verifiable 5. Consistent 6. Ranked for import and/or stability 7. Modifiable 8. Traceable
- 4. Components of an SRS 1. Functionality 2. Performance 3. Design constraints imposed on an implementation 4. External interfaces
- 5. Structured Analysis Data flow based modeling, often referred to as the structured analysis technique, uses function-based decomposition while modeling the problem. > A DFD shows the flow of data through a system. It views a system as a function that transforms the inputs into desired outputs. Any complex system will not perform this transformation in a single step, and a data will typically undergo a series of transformations before it becomes the output. The DFD aims to capture the transformations that take place within a system to the input data so that eventually the output data is produced.
- 7. DFD : Choice of Symbol • Sarson Yourdan 1.0 1.0 Process Process Description Description entity name entity name Data Store Data Store name name Data Flow Name Data Flow Name
- 8. Example