"Freedom" Service-Oriented Methodology

Information-hiding Secrets

Original versus Modern

Original Concept	Modern Realization
Hardware-Hiding Module	Device driver
Software Decision Module	Classes and objects encapsulating -- data structures -- algorithms
Behavior-Hiding Module	NOTHING!

Behavior-Hiding has the biggest payoff of the 3
- Maintenance: Most post-delivery changes add capability (requirements changes)
- Development: Potential for reusable requirements at code level

".. the most promising ideas ... are already here and have been here for years but are not being used .."
- Dr. David L. Parnas, SigSoft Software Engineerng Notes, 1999