Chapter 31
Reengineering
CHAPTER OVERVIEW AND COMMENTS
Reengineering became ‘corporate chic’ during the 1990s. At the corporate level, entire business processes were reengineered to make them more efficient and more competitive (at least in theory!). These changes had a trickle down effect on information systems. As business processes changed, the information technology that supported them also had to change.
The intent of this chapter is to introduce business process reengineering (BPR) and discuss the management and technical aspects of software reengineering. The basic principles of BPR are introduced and an overall model for reengineering the business is discussed briefly. In reality BPR is a topic that is beyond the scope of most courses that use SEPA. It is introduced in this chapter because it is the driving force behind most software reengineering activities.
The discussion of software reengineering begins with the “maintenance iceberg.” Even after almost 40 years, this metaphor rings true, and yet, many students have virtually no appreciation of the burden that maintenance places on the software community. The steps of the software reengineering process model are considered in some detail. A model for assessing the economics of software reengineering is presented at the conclusion of the chapter.
Critical Points: BPR extends beyond the scope of software to the entire business. Yet the results of BPR can have a profound impact on information systems that service a business. Software maintenance is a significant burden for all software organizations. The software reengineering process encompasses inventory analysis, restructuring, reverse engineering, and forward engineering.
31.1 Business Process Reengineering
This section presents an overview of BPR with an emphasis on its impact, basic BPR principles and the tasks that define the BPR model. Be sure to spend a moment on Section 31.1.4. There is significant hype associated with BPR and the ramifications of this should be discussed for your students.
If time permits you might have the student conduct a BPR exercise by reengineering some process (e.g., registration) at your university. Follow the process outlined in this section
31.2 Software Reengineering
It’s worth spending substantial time discussing software maintenance (Section 30.2.1) and its impact on the software community. The basic activities that are performed when software is to be reengineered are discussed in Section 30.2.2. The discussion begins with software maintenance and then continues into an overview of the software reengineering process model. Each task performed as part of the model is discussed briefly.
31.3 Reverse Engineering
This section considers reverse engineering activities and identifies key concepts that must be understood as information is extracted from an existing program. Reverse engineering techniques for processing, data, and user interfaces are all discussed. If time permits, distribute two undocumented pieces of code, one well structures and designed, the other a kludge. Have your students attempt to reverse engineer each and then draw conclusions from their experience.
31.4 Restructuring
Section 31.4 presents a brief overview of restructuring techniques for code and data. If time permits have students research one or more restructuring tools (see the sidebar in this section) and then discuss how they work on existing code.
31.5 Forward Engineering
This section presents an overview of forward engineering approaches for client/server systems, OO systems, and user interfaces.
31.6 The Economics of Reengineering
This section presents a simple cost-benefit model for reengineering. Not every application should be reengineered. The model presented in this section enables your students to compute the projected cost benefit of a reengineering activity.
No comments:
Post a Comment