Data dependencies between processes create scheduling interactions that limit the times at which processes may execute. Processes are then designed to fit available windows in the overall system schedule. The result is often a system with very sensitive timing that is hard to understand and maintain. Object values are extended to object histories in which a sequence of time constrained values describe the evolution of the object over time.
Systems comprise a set of objects and their dependencies.
The TSO model describes the effects of object operations and the propagation of change among related objects. Periodic objects, a class of objects within the TSO model, are described in detail in this article and compared with traditional periodic processes. The Digital Library is published by the Association for Computing Machinery.