58,184 research outputs found
Minimum Equivalent Precedence Relation Systems
In this paper two related simplification problems for systems of linear
inequalities describing precedence relation systems are considered. Given a
precedence relation system, the first problem seeks a minimum subset of the
precedence relations (i.e., inequalities) which has the same solution set as
that of the original system. The second problem is the same as the first one
except that the ``subset restriction'' in the first problem is removed. This
paper establishes that the first problem is NP-hard. However, a sufficient
condition is provided under which the first problem is solvable in
polynomial-time. In addition, a decomposition of the first problem into
independent tractable and intractable subproblems is derived. The second
problem is shown to be solvable in polynomial-time, with a full
parameterization of all solutions described. The results in this paper
generalize those in [Moyles and Thompson 1969, Aho, Garey, and Ullman 1972] for
the minimum equivalent graph problem and transitive reduction problem, which
are applicable to unweighted directed graphs
A Business Process Management System based on a General Optimium Criterion
Business Process Management Systems (BPMS) provide a broad range of facilities to manage operational business processes. These systems should provide support for the complete Business Process Management (BPM) life-cycle (16): (re)design, configuration, execution, control, and diagnosis of processes. BPMS can be seen as successors of Workflow Management (WFM) systems. However, already in the seventies people were working on office automation systems which are comparable with todayâs WFM systems. Recently, WFM vendors started to position their systems as BPMS. Our paperâs goal is a proposal for a Tasks-to-Workstations Assignment Algorithm (TWAA) for assembly lines which is a special implementation of a stochastic descent technique, in the context of BPMS, especially at the control level. Both cases, single and mixed-model, are treated. For a family of product models having the same generic structure, the mixed-model assignment problem can be formulated through an equivalent single-model problem. A general optimum criterion is considered. As the assembly line balancing, this kind of optimisation problem leads to a graph partitioning problem meeting precedence and feasibility constraints. The proposed definition for the "neighbourhood" function involves an efficient way for treating the partition and precedence constraints. Moreover, the Stochastic Descent Technique (SDT) allows an implicit treatment of the feasibility constraint. The proposed algorithm converges with probability 1 to an optimal solution.BPMS, control assembly system, stochastic optimisation techniques, TWAA, SDT
Flexible resources allocation techniques: characteristics and modelling
At the interface between engineering, economics, social sciences and humanities, industrial engineering aims to provide answers to various sectors of business problems. One of these problems is the adjustment between the workload needed by the work to be realised and the availability of the company resources. The objective of this work is to help to find a methodology for the allocation of flexible human resources in industrial activities planning and scheduling. This model takes into account two levers of flexibility, one related to the working time modulation, and the other to the varieties of tasks that can be performed by a given resource (multiâskilled actor). On the one hand, multiâskilled actors will help to guide the various choices of the allocation to appreciate the impact of these choices on the tasks durations. On the other hand, the working time modulation that allows actors to have a work planning varying according to the workload which the company has to face
Parallel algorithms for two processors precedence constraint scheduling
The final publication is available at link.springer.comPeer ReviewedPostprint (author's final draft
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