The Software Process-Software Engineering-Lecture Slides, Slides of Software Engineering

Download The Software Process-Software Engineering-Lecture Slides and more Slides Software Engineering in PDF only on Docsity! CS 501: Software Engineering Fall 2000 Lecture 2 The Software Process docsity.com 2 Books  Frederick P. Brooks, Jr. The Mythical Man Month. Addison-Wesley, 1972.  Ian Sommerville, Software Engineering, 6th edition. Addison-Wesley, 2000.  Grady Booch, James Rumbach, Ivar Jacobson, The Unified Modeling Language. Addison-Wesley 1999. See the Readings page on the CS 501 Web Site docsity.com 5 The Software Process (Simplified) Requirements Operation and Maintenance Implementation Design Feasibility and Planning docsity.com 6 The Waterfall Model Requirements Definition System and Software design Programming and Unit Testing Integration and System Testing Operation and Maintenance docsity.com 7 Requirements Analysis and Definition The system's services, constraints and goals are established by consultation with system users. They are then defined in a manner that is understandable by both users and development staff. This phase can be divided into:  Feasibility study (often carried out separately)  Requirements analysis  Requirements definition  Requirements specification docsity.com 10 Integration and System Testing The individual program units are:  integrated and tested as a complete system  tested against the requirements as specified  delivered to the client docsity.com 11 Operation and Maintenance  Operation: The system is put into practical use.  Maintenance: Errors and problems are identified and fixed.  Evolution: The system evolves over time as requirements change, to add new functions or adapt the technical environment.  Phase out: The system is withdrawn from service. docsity.com 12 Discussion of the Waterfall Model Advantages:  Process visibility  Dependence on individuals  Quality control  Cost control Disadvantages: Each stage in the process reveals new understanding of the previous stages, that requires the earlier stages to be revised. docsity.com Iterative Refinement Evaluation Requirements io [—— | (prototype) docsity.com Implementation 16 Iterative Refinement Outline Description Concurrent Activities Requirements Design Implementation Initial Version Intermediate Versions Final Version docsity.com 17 Iterative Refinement & Software Process Outline Description Concurrent Activities Requirements Design Implementation Final Version docsity.com 20 Iterative Refinement + Waterfall Model: Graphics for Basic Design Issues:  Pictorial subprograms: coordinate systems, window/viewport  User specification of perspective Design Strategy: (Iterative Refinement)  Write a series of prototypes with various proposed semantics  Evaluate with a set of programming tasks docsity.com 21 Iterative Refinement + Waterfall Model: Graphics for Basic Phase 1: Implementation (Waterfall)  When the final specification was agreed, the entire preprocessor and run-time support were recoded.  The system was almost entirely bug-free. Phase 2: New compiler (Waterfall) Phase 1 was used as the requirements definition for the final version. docsity.com 22 Observations about Software Processes Completed projects should look like the Waterfall Model but ... the development process is always partly evolutionary. Risk is lowered by:  Prototyping key components  Dividing into phases  Following a visible software process  Making use of reusable components docsity.com