Routing, scheduling, timing and intractability

The management of the various cooperation modes and timing requirements in the case of a large number of tasks poses interesting theoretical problems in massively parallel environments. These systems are in general fully distributed ones, preventing coherent observability. Moreover, their configurations may change dynamically because of failures and/or modifications. Thus no optimal algorithms can be constructed for the effective utilization of the resources available. The influence of the granularity level, cooperation modes and timing requirements are scrutinized in order to identify areas for further research. It is shown that the resource allocation procedure should be partitioned into distinct phases both in time and space.<>