Next: , Up: Dezyne external Summary   [Contents]

4.4.1 Understand when to use ‘external’ and what problems it solves

Mark as ‘external’ any requires interface containing out-events that is delegated to the boundary of a system. This was discussed at length in What does ‘external' do and when should you use it? after an analysis of the Alarm System implementation we made in earlier tutorials showed that illegal behaviour could occur.