1 Advanced Computer Programming Project Management: Software Life Cycle Copyright © Texas Education Agency, 2013

Overview Basics Requirements Design Implementation Verification Deployment Maintenance Waterfall Implementation Iterative Implementation 2Copyright © Texas Education Agency, 2013

Basics Software Design consists of five essential steps in the “life cycle” of development: Requirements Design Implementation Verification Maintenance 3Copyright © Texas Education Agency, 2013

Requirements The requirements phase is a period of collecting information from a user or customer on what they want a piece of software to do. It is critical to ensure you understand what the customer or client wants in order to provide the correct software solution. 4Copyright © Texas Education Agency, 2013

Requirements: Potential Pitfalls Things that can go wrong in requirements gathering: Client says one thing but means something else Not all requirements are specified (incomplete specification) Misunderstanding about what the client wants 5Copyright © Texas Education Agency, 2013

Design Design of a software product is the process of analyzing requirements provided by a customer or client and determining the most efficient and appropriate software solution. The level of detail in the design is dependent upon the type of software development methodology you are using. 6Copyright © Texas Education Agency, 2013

Design: Potential Pitfalls Things that can go wrong during design: Misinterpretation of requirements Inefficient or wrong solution to a problem Incomplete or over-complicated design 7Copyright © Texas Education Agency, 2013

Implementation Implementation is the process of turning the design of the software into a working program. 8Copyright © Texas Education Agency, 2013

Implementation: Potential Pitfalls Things that can go wrong during implementation: Implementing faulty or “buggy” code Misinterpretation of design Not following the design and “doing your own thing” Mismatched components preventing integration Lack of communication between developers Overwriting or deleting someone else’s work Not understanding someone else’s code and changing how it works 9Copyright © Texas Education Agency, 2013

Verification Verification is the process of testing software to ensure it meets the requirements presented by the user, as well as determining if the software is of high quality and relatively free of defects. This phase is also commonly called Testing or Quality Assurance. 10Copyright © Texas Education Agency, 2013

Verification: Potential Pitfalls Things that can go wrong during verification: Incomplete tests (not testing for something you should) Ignoring test results Misinterpreting test results 11Copyright © Texas Education Agency, 2013

Deployment Deployment is the delivery of functional software to the client or end user. In some methods of development, this is the last step in the actual development process leaving only maintenance of the product. In other methods, such as iterative, addition of new features continues until the user no longer wishes to continue the project. 12Copyright © Texas Education Agency, 2013

Maintenance Once a software solution is verified to be “correct,” it is deployed to the client and enters a stage of maintenance. During maintenance, the client will provide feedback on errors and changes they want in the system which must be corrected. It is not uncommon during maintenance to perform all of the steps of the Software Life Cycle. 13Copyright © Texas Education Agency, 2013

Maintenance: Potential Pitfalls Things that can go wrong during maintenance: Misinterpretation of requests from client “Fixing” something that isn’t broken Almost any of the concerns that may arise during the rest of the software life cycle 14Copyright © Texas Education Agency, 2013

Waterfall Model In the waterfall model, each step is performed in sequence. 15 Requirements Design Implementation Maintenance Verification Deployment Copyright © Texas Education Agency, 2013

Iterative Model In the iterative model, there is an initial planning phase, then a series of development iterations, each iteration adding functionality to the product. 16 Requirements Design Implementation Verification Deployment Maintenance Change Requirements Copyright © Texas Education Agency, 2013