Contingency?
No best way to do something, as it is contingent upon the internal and external situation - level of uncertainty and turbulence.
Spiral model?
Boehm 1988
Novelty?
Austin & Delvin 2009, novel = output der er forskellig fra hvordan det var før. Post-industrial idea er bedre end industrial hvis novelty benefit er højere end novelty cost.
Ambidexterity?
Ramasubbu et al 2011; Balancere elementer i ISD; Tradeoffs: Flex/effeciency, productivity/quality, development/maintenance performance