Forward Engineering
1.     The cost to maintain one line of source code may be 20 to 40
times the cost of initial development of that line.
2.     Redesign of the software architecture (program and/or data
structure), using modern design concepts, can greatly facilitate
future maintenance.
3.     Because a prototype of the software already exists,
development productivity should be much higher than average.
4.     The user now has experience with the software. Therefore,
new requirements and the direction of change can be
ascertained with greater ease.
5.   CASE tools for reengineering will automate some parts of
the job.
6.     A complete software configuration (documents, programs
and data) will exist upon completion of preventive maintenance.