ISBN : 978-81-963532-2-3 (E-Book) • β –testing: It is the system testing performed by a friendly set of customers. • Acceptance testing: It is the system testing performed by the customer himself after the product delivery to determine whether to accept or reject the delivered product. System testing is normally carried out in a planned manner according to the system test plan document. The system test plan identifies all testing-related activities that must be performed,specifies the schedule of testing, and allocates resources. It also lists all the test cases and the expected outputs for each test case. Maintenance: -Maintenance of a typical software product requires much more than the effort necessary to develop the product itself. Many studies carried out in the past confirm this and indicate that the relative effort of development of a typical software product to its maintenance effort is roughly in the 40:60 ratios. Maintenance involves performing any one or more of the following three kinds of activities: • Correcting errors that were not discovered during the product development phase. This is called corrective maintenance. • Improving the implementation of the system, and enhancing the functionalities of the system according to the customer’s requirements. This is called perfective maintenance. • Porting the software to work in a new environment. For example, porting may be required to get the software to work on a new computer platform or with a new operating system. This is called adaptive maintenance. Shortcomings of the classical waterfall model The classical waterfall model is an idealistic one since it assumes that no development error is ever committed by the engineers during any of the life cycle phases. However, in practical development environments, the engineers do commit a large number of errors in almost every phase of the life cycle. The source of the defects can be many: oversight, wrong assumptions, use of inappropriate technology, communication gap among the project engineers, etc. These defects usually get detected much later in the life cycle. For example, a design defect might go unnoticed till we reach the coding or testing phase. 13 Software Engineering Keerthana P, Manasa KN, Ganga D Bengal
19 Publizr Home