香港理工大学-软件进化与维护3.doc

3.1 Learning Objectives At the end of this unit you should be able to understand: the international processes of software maintenance the availability of maintenance supporting tools the software engineering environment the use of ontology 3.2 Learning Flow In this unit, we cover the following topics: IEEE Standard for Software Maintenance ISO Standard for Software Maintenance Maintenance supporting tools Process-Sensitive SE Environments Ontology 3.3 Processes The processes of software maintenance are not limited to modifying just the software:- Modifying the software typically modifies part of the machines services in a system Not all software maintenance involved making changes only to the software implantations of business rules Some software maintenance changes the systems documentation The largest part of software maintenance does not only modify the software. - it leaves the code and the documentation unchanged. What it does is to use the code and the documentation to:- 1. build or refresh the systems personnels knowledge and understanding of the system and its software; 2. support consultation with users 3. validate of test the software as a whole (e.g. regression testing) 4. provide basis for answering managerial questions 5. assist training in use of the system 6. serve as basis in helping management devise ways to give the organization new or changed functionality through different and changed uses of the existing systems The basic steps of software maintenance includes: 1. understand the problem or requirement for change 2. identify and describe the changes to be made to the system 3. make the changes 4. test the changed software, and regression testing 5. implement the upgraded system and assessing the entire system at the post implementation review 3.4 IEEE Standard for Software Maintenance The IEEE Standard 1219-1998 describes an iterative process for managing and executing software maintenance ac