nCorrectness --Conforming to specifications
nMaintainability--Modification with minimal difficulty.
nComposing module that are:
uhighly cohesive.
uweakly coupled.
nThree design principles:
uinformation hiding
ucontinuity
uopen/closed
nsoftware as a temporary solution.
nSoftware as data design followed by algorithm design.
nSoftware as both an English document and mathematical document.