Characteristics of optimal workload allocation for closed queueing networks

We consider the problem of allocating a given workload among the stations in a multi-server product-form closed queueing network to maximize the throughput. We first investigate properties of the throughput function and prove that it is pseudoconcave for some special cases. Some other characteristics of the optimal workload and its physical interpretation are also provided. We then develop two computational procedures to find the optimum workload allocation under the assumption that the throughput function is pseudoconcave in general. The primary advantage of assuming pseudoconcavity is that, under this assumption, satisfaction of first order necessary conditions is sufficient for optimality. Computational experience with these algorithms provides additional support for the validity of this assumption. Finally, we generalize the solution procedure to accommodate bounds on the workloads at each station.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29251/1/0000308.pd

The optimal configuration and workload allocation problem in flexible manufacturing systems

In this article we consider the problem of determining the minimum cost configuration (number of machines and pallets) for a flexible manufacturing system with the constraint of meeting a prespecified throughput, while simultaneously allocating the total workload among the machines (or groups of machines). Our procedure allows consideration of upper and lower bounds on the workload at each machine group. These bounds arise as a consequence of precedence constraints among the various operations and/or limitations on the number or combinations of operations that can be assigned to a machine because of constraints on tool slots or the space required to store assembly components. Earlier work on problems of this nature assumes that the workload allocation is given. For the single-machine-type problem we develop an efficient implicit enumeration procedure that uses fathoming rules to eliminate dominated configurations, and we present computational results. We discuss how this procedure can be used as a building block in solving the problem with multiple machine types.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45516/1/10696_2004_Article_BF00170207.pd

Production planning for flexible flow systems with limited machine flexibility

http://deepblue.lib.umich.edu/bitstream/2027.42/35830/2/b1908315.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/35830/1/b1908315.0001.001.tx

An Integrated design support method for flexible assembly systems

http://deepblue.lib.umich.edu/bitstream/2027.42/35829/2/b1793871.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/35829/1/b1793871.0001.001.tx

Production planning for flexible flow systems with limited machine flexibility

A flexible manufacturing system (FMS) is highly capital-intensive and FMS users are concerned with achieving high system utilization. The production planning function for setting up an FMS prior to production should be developed in order to make the most of the potential benefits of FMSs. We consider two production planning problems of grouping and loading a flexible flow system, which is an important subset of FMSs where the routing of parts is unidirectional. We show that considering this routing restriction as well as limited machine flexibility strongly affects both the solution techniques and the quality of the solutions. Because of the complexity of the problem, we present a heuristic approach that decomposes the original problem into three interrelated subproblems. We show that the proposed approach usually finds a near-optimum solution and is superior to an approach that exists in the literature of FMS production planning. We also introduce effective heuristic methods for two new subproblems that arise because of the unidirectional flow precedence and flexibility constraints. Computational results are reported and future research issues are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45895/1/10756_2004_Article_206673.pd

A line balancing strategy for designing flexible assembly systems

http://deepblue.lib.umich.edu/bitstream/2027.42/6202/5/bal9381.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/6202/4/bal9381.0001.001.tx

Issues in the design and operation of flexible assembly systems for large products : a simulation study

http://deepblue.lib.umich.edu/bitstream/2027.42/8387/5/bam3208.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/8387/4/bam3208.0001.001.tx

A framework for capacity planning and machine configuration in flexible assembly systems

http://deepblue.lib.umich.edu/bitstream/2027.42/6201/5/bam4519.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/6201/4/bam4519.0001.001.tx

Some characteristics of optimal workload allocation for closed queueing networks

http://deepblue.lib.umich.edu/bitstream/2027.42/6204/5/bal9379.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/6204/4/bal9379.0001.001.tx