Change Management

Software Management

Types of Maintenance

The types of maintenance are minor modifications, restructuring, reengineering, or rebuilding. Minor modifications are changes to existing code and can be any of the project manager classifications discussed above. Restructuring is the redevelopment of a portion of an application with a bridge to the old application. Reengineering is the reverse analysis of an old application to conform to a new methodology, usually Information Engineering or object orientation. Reengineering is also known as reverse engineering. Rebuilding is the retirement and redevelopment of an application.

To select the appropriate type of maintenance, several questions are asked (see Figure 18-12). First, ask if the software works. If the answer is no, you retire the old application. Then you reengineer and rebuild it using a methodology. If the answer is yes, you continue to the next question: Does the application have a high maintenance cost? If the maintenance cost is low, the answer is no; then do a simple revision. If the answer is yes, immediately restructure the parts that do not work, and reengineer the entire application as part of on-going work.

Functional Specification Settlements



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The settlements system uses relational database design techniques and fully normalized data entities 1 The database design is fully documented in Figure 2-1. The diagram shows the 17 entities used m settlements processing and the relationships between them Each entity and its descriptive attributes are fully described in the data dictionary attached as Appendix 1; they are also available on-line through both IEF, the CASE tool being used for the application, and Project- Notes, the on-line help tool.






1 Prior to January. 1994. a nonnormalized, relational approach to the data was used. This resulted In a loss of data integrity that necessitated strict enforcement of relational theory to comply with audit requirements for the application.

FIGURE 18-11 Sample Documentation Change with Old Contents

FIGURE 18-12 Decision Tree for Selecting the Maintenance Type