1. Program Restructuring
Modify source code and data in order to make it amenable to future changes
Code restructuring
Design with same function with higher quality than original program
Data restructuring
Involves restructuring the database or the database schema
May involve code restructuring

2. Software Engineering II
Lecture 40
Fakhar Lodhi

3. Recap

4. Forward Engineering
Application of SE principles, methods, and concepts to re-create an existing application
In most cases forward engineering does not simply create a modern equivalent of an older program, rather new user and technology requirements are integrated into the reengineering effort.

5. The Economics of Reengineering
Cost benefit analysis
P1 : current annual maintenance cost for an application
P2 : current annual operation cost for an application
P3 : current annual business value of an application
P4 : predicted annual maintenance cost after reengineering
P5 : predicted annual operations cost after reengineering

6. The Economics of Reengineering
P6 : predicted annual business value cost after reengineering
P7 : estimated reengineering cost
P8 : estimated reengineering calendar time
P9 : reengineering risk factor (1.0 is nominal)
L : expected life of the system

7. The economics of reengineering
C maintenance = [P3 – (P1 + P2)] x L
Where
P1 = current annual maintenance cost for an application
P2 = current annual operation cost for an application
P3 = current annual business value of an application
L = expected life of the system

8. The economics of reengineering
C reengineering = [P6 – (P4 + P5) x (L – P8) – (P7 x P9)]
Where
P4 = predicted annual maintenance cost after reengineering
P5 = predicted annual operations cost after reengineering
P6 = predicted annual business value cost after reengineering
P7 = estimated reengineering cost
P8 = estimated reengineering calendar time
P9 = reengineering risk factor (1.0 is nominal)
L = expected life of the system