Software Processes
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This document discusses different software process models, including the waterfall model, prototype model, iterative enhancement model, and spiral model. It explains that a software process is a method for developing or producing software and is important for organizations to define for projects. The main aims of process models are to be descriptive, prescriptive, and explanatory. Process models can be used to organize, plan, staff, budget, schedule and manage projects.
Software Processes
- 2. CMC Limited Objectives After completion of this chapter you will be able to: o Waterfall model o Prototype model o Iterative enhancement model o Spiral model • Understand what is process and its importance • Explain the purpose of software process • Understand different software process models
- 3. CMC Limited Introduction The software process is a becoming a big issue for companies that produce software. As a consequence, the software process is becoming more and more important for permanent employees, long-term practitioners, and short- term consultant in the software industry. A process may be defined as a method of doing or producing something. Extending this to the specific case of software, we can say that a software process is a method of developing or producing software
- 4. CMC Limited The Importance of Process Introduction contd.. So it is important for each organization to define the process for a project. At its most basic, this means simply to write it down. Writing it down specifies the various items that must be produced and the order in which they should be produced: from plans to requirements to documentation to the finished source code. It says where they should be kept, and how they should be checked, and what to do with them when the project is over. It may not be much of a process. However, once you have written it down, it is a defined process
- 5. CMC Limited Purpose of Process Introduction contd.. Effectiveness Not to be confused with efficiency. An effective process must help us produce the right product. It doesn't matter how elegant and well-written the software, nor how quickly we have produced it. Maintainability However good the programmer, things will still go wrong with the software. Requirements often change between versions. In any case, we may want to reuse elements of the software in other products.
- 6. CMC Limited Purpose of Process contd.. Predictability Any new product development needs to be planned, and those plans are used as the basis for allocating resources: both time and people. It is important to predict accurately how long it will take to develop the product Repeatability If a process is discovered to work, it should be replicated in future projects. Ad-hoc processes are rarely replicable unless the same team is working on the new project. Quality Quality in this case may be defined as the product's fitness for its purpose. One goal of a defined process is to enable software engineers to ensure a high quality product.
- 7. CMC Limited Software Development Process Models Main aims of process models: • Descriptive • Prescriptive • Explanatory
- 8. CMC Limited Software Development Process Models contd.. Uses of Development Process Models A development process is a set of activities, which are performed according to specified order to get the desired output. It is an abstract representation of a development process. Following are the important uses of these models: • As a means to organize, plan, staff, budget & schedule and manage software projects. • As a perspective outline of the required set of documents to be produced. • As a basis for determining which software engineering tools and methodologies will be most appropriate.
- 9. CMC Limited Process Models Waterfall Model This is the simplest software process model. In this model, the phases are organized in a linear order. The sequence of activities that Waterfall model contains is feasibility analysis, requirement analysis and project planning, system design, detailed design, coding and unit testing, system integration and testing. Software Development Process Models contd..
- 10. CMC Limited Process Models contd.. Waterfall Model
- 11. CMC Limited Prototype Model Sometimes the developer is not sure of the efficiency of an algorithm, the form of human machine interaction. These and many other situations are common for a large and complex system for which there is no manual system exists. To develop software products for such problems, a prototyping model is used Process Models contd.. Prototyping Model
- 12. CMC Limited Process Models contd.. Iterative Enhancement Model The iterative model combines the features of both waterfall and prototype model. It supports the incremental building of the new system. This approach results in better testing. This is because testing in increments is easier than testing the whole system at once. Iterative Model
- 13. CMC Limited Process Models contd.. Spiral Model This is a recent model proposed by Boem. This model combines the best features of both classic life cycle and prototyping. The activities in this model are organized like a spiral that has many cycles Spiral Model