We evoke our model of strict periodic systems with precedence constraints and our model of architecture. We prove that the problem of multiprocessor scheduling of these systems is NP-hard. We give some theoretical results which allows us to propose a heuristic to solve this problem and we compare its performances to those of an exact algorithm of type “branch & bound”.

The Resource-constrained Project Scheduling Problem (Rcpsp), in which a schedule must obey the resource constraints and the precedence constraints between pairs of activities, is one of the most studied scheduling problems. An important variation of the problem (RcpspDc) is to find a schedule which maximises the net present value (discounted cash flow), when every activity has a given cash flow...

The Resource Constrained Project Scheduling Problem is an important problem in project management, manufacturing and resource optimization. We focus on a variant of RCPSP with time lags and uncertain activity durations. We adopt a Precedence Constraint Posting approach and add precedence constraints to the original project graph so that all resource conflicts are solved and a consistent assignm...

This paper presents the design and implementation of a constraint-based virtual environment for supporting interactive assembly and maintenance tasks within an immersive virtual reality environment. The system architecture of the constraint-based virtual environment is based on the integration of components such as OpenGL Optimizer, Parasolid geometric kernel, a Constraint Engine and an Assembl...

Distributed computing systems often need to consider the scheduling problem involving a collection of highly dependent data-processing tasks that must work in concert achieve mission-critical objectives. This paper considers unrelated machine for minimizing weighted sum completion time under arbitrary precedence constraints and on heterogeneous machines with different processing speeds. The is ...

We study two related problems in non-preemptive scheduling and packing of malleable tasks with precedence constraints to minimize the makespan. We distinguish the scheduling variant, in which we allow the free choice of processors, and the packing variant, in which a task must be assigned to a contiguous subset of processors. For precedence constraints of bounded width, we completely resolve th...

We present a new parallel algorithm for the two processors scheduling problem. The algorithm uses only O(n 3) processores and takes time O(log 2 n) time on a PRAM. In order to prove the above bounds we show how to compute in NC the lexicographically rst matching for a special kind of convex bipartite graphs.

This paper discusses the scheduling of precedence-related jobs non-preemptively in a job shop environment with an objective of minimizing the makespan. Due to the NP-hard nature of the scheduling problems, it is usually difficult to find an exact optimal schedule and hence one should rely on finding a near to optimal solution. This paper proposes a computationally effective powers-of-two heuris...

We present an algorithm that finds an optimal schedule on a single processor for a given set of processes such that each process starts executing after its release time and completes its computation before its deadline, and a given set of precedence relations and a given set of exclusion relations defined on ordered pairs of process segments are satisfied. This algorithm can be applied to the i...