A set of unit·time tasks has to be processed on identical parallel processors subject to precedence constraints and unit·time communication delays; does there exist aschedule of length at most d? The problem has two variants, depending on whether the number of processors is res· trictively small or not. For the first variant the question can be answered in polynomial time for d =3 and is NP-com...

In the simple assignment problem, there are n processors, m tasks, and a relation between the processors and tasks; this relation indicates the ability of the processor to perform the task. When the processors fail independently with known probabilities, two performance issues arise. First, with what probability can the operating processors all be kept busy? Second, with what probability can th...