Seamless Object-Oriented Requirements

Design by Contract enables seamless software development by unifying software requirements with their implementations. In its pure form, however, Design by Contract leaves some problems with contracts' expressiveness, verifiability, and reusability open. These problems significantly reduce practical applicability of seamless development. The present article introduces seamless object-oriented requirements - a novel approach to seamless development that builds upon Design by Contract and now-available advanced program proving tools. The article explains and illustrates the new approach, concluding with a quantitative evaluation of the extent to which the approach fixes the problems of traditional contracts.