Search results

A number of simulation studies were conducted by several researchers in order to compare performances of cellular and functional layouts. The methodologies used by these studies either present several objectivity lacks or are highly time‐consuming. The purpose of this paper is to propose a novel and objective methodology, based on the coupling of simulation and the Taguchi method.

Simulation models for both layouts are first developed. Simulations are then conducted following a standard Taguchi orthogonal array. Subsequently, the obtained results are analyzed using the analysis of variance technique. Finally, a mathematical model is built, and validated by the confirmation test.

The proposed comparison method permitted to obtain a valid mathematical model used to predict the superiority rank of the two layouts within the scope of the paper.

This paper presents a novel objective methodology for comparing functional and cellular layouts.

The purpose of this research is to focus on the solution of the resource sizing problem for production systems (PSs), defined as the specification of the number of each type of resources to be used in a production process for a given time period.

The resource sizing problem is tackled by a simulation‐expert‐system‐based approach, coupling an expert system (ES) with a simulation tool. Hence, a number of “simulation – ES optimization” cycles are realized until obtaining non‐improvable levels of performance. The main performance measures considered in this work are related to the manufacturing orders due dates (DD).

Through the approach proposed in this work, it is possible to size machines in order to optimize DD related performance measures for a PS belonging to a specific application domain. PSs of this domain are characterized by a functional layout and feature no labor constraints. In addition, machines belonging to a same department are considered to be identical.

The developed approach allows studying the machine sizing problem realistically, through the use of stochastic simulation. Also, by coupling an ES to the simulation tool, it avoids the try and error aspect characterizing most simulation‐based approaches. It hence features a well‐structured reasoning mechanism for the search of the best solution.

A number of simulation studies have been conducted previously by several researchers, in order to compare the performance of cellular and functional layouts. The purpose of this paper is to highlight the lack of objectivity of a number of these studies, in order to explain the origin of their conflicting conclusions.

A taxonomy of the main experimental factors and performance measure used in the main simulation comparative studies is followed by a critical assessment of ten of these studies. The analysis is focused on the objectivity of the layout comparison methodologies. Then, the determined shortcomings are categorized and some of them are illustrated by way of simulation.

The revealed shortcomings are most likely responsible for the conflicting conclusions of the studies and may well explain what is called in the literature the “cellular paradox.”

This work sets up the basis for an objective comparison methodology between the two manufacturing system layouts. Such a methodology should in fact be free of all the highlighted objectivity flaws.

The aim of this paper is to illustrate a solution that can be used to reduce the severity of breakdowns and improve performances in the cellular manufacturing (CM) system with unreliable machines.

The performance of CM system is conditioned by disruptive events, such as the failure of machines, which randomly occurs and penalizes the performance of the cells, seriously disturbing the smooth working of the factory. To overcome the problem caused by the breakdowns, the authors develop a solution, based on the principle of virtual cell and the notion of intercellular transfer that can improve the availability of the system. In this context, the use an analytical method based on Markov chains to model the availability of the cell. The results are validated using simulation.

The proposed solution in this paper confirmed that it is possible to reduce the severity of breakdowns in the CM system and improve the availability of the cells through an intercellular transfer created at the time of a breakdown. Simulation allowed a validation of the analytical model and showed the contribution of the suggested solution.

The developed approach studies the performance of the production cells formed by unreliable machines. It uses the notion of the intercellular transfer to improve the availability of the cells.