Reuse Metrics

Dr. Jeffrey Poulin identifies 3 fundamental metrics useful in measuring software reuse:

1) Relative cost of writing for reuse (RCWR)
Developing s/w intended to be reused requires incremental effort. Poulin estimates that it requires 50% more effort to write a reusable component.

2) Relative cost to reuse (RCR)
Reusing components designed for reuse doesn't eliminate 100% of effort. There is a cost of 20% assigned to reuse preexisting components.

3) Software reuse payoff
Using these simple metrics, s/w reuse achieves breakeven within 1 reuse of a component ie. using an RCWR of 1.5 and an RCR of 0.2.

This s/w reuse metrics can form a reasonable baseline to justify services reuse in SOA scenario.