The design and development of real-time systems is often a difficult and time-consuming task. System realization has become increasingly difficult due to the proliferation of larger and more complex applications. To offset some of these difficulties, real-time developers have turned to object-oriented methodology. The success of object-oriented concepts in the development of non-real-time programs motivates the relevance of these concepts to achieve similar gains from encapsulation and code reuse in the real-time domain. This article presents an approach of integrating real-time constraint specifications within the constructs of an object-oriented language, affording these constraints a status equivalent to other language elements. This has led to the definition of such novel concepts as temporal abstract classes, virtual temporal constraints, and temporal specification inheritance, which extends inheritance mechanisms to accommodate real-time constraint specifications. These extensions provide real-time developers with the ability to manage and maintain the temporal behavior of a real-time program in a comparable manner to its functional behavior.
