A framework and a simulation generator for kanban-controlled manufacturing systems

A generalized framework for the definition of kanban-controlled manufacturing systems and a simulation generator based on this framework are introduced in this paper. Kanbans are used between and within workstations to trigger product flow or production. The simulation generator is capable of modeling complex manufacturing systems with multiple parts, multiple work centers and multiple processes at each work center. Multiple process definition capability enables users to define convergent and divergent points in a manufacturing system. Several decision rules are defined and incorporated into the generator. The simulation generator can be used as a completely interactive tool that is data-driven and requires no programming skills.     

Modular production systems: a new manufacturing paradigm

It is well recognized that manufacturers of consumer goods throughout the world are facing major new demands, including shorter product life-cycles and increasing competition. In response, companies are restructuring and moving away from traditional process-centred work practices in favour of concurrent engineering methods. In particular, design for manufacture has gained widespread recognition as a means of reducing production costs and lead times. However, optimal design for manufacture is difficult to achieve using current-day work organization and business structures. An underlying problem is the lack of a scientific framework for production. To address this need, this paper proposes a radical and far-reaching new manufacturing paradigm based upon on building production systems from standardized modular machines. The manufacturing concept, termed modular production systems (MPS), is aimed specifically at hard low- to medium-technology consumer products, as typified by goods such as childrens toys and kitchen appliances. The rationale for MPS as a means of enabling concurrent product and production system design is put forward, and the long-term implications and work required to establish the concept are discussed.     

Loading flexible manufacturing systems: a heuristic approach

In this study, heuristic algorithms are developed for loading Flexible Manufacturing Systems. The heuristic approach is an efficient way of planning the FMS with multiple nonlinear loading objectives.     

Reconfigurable manufacturing systems: Key to future manufacturing

Presented in this article is a review of manufacturing techniques and introduction of reconfigurable manufacturing systems; a new paradigm in manufacturing which is designed for rapid adjustment of production capacity and functionality, in response to new market conditions. A definition of reconfigurable manufacturing systems is outlined and an overview of available manufacturing techniques, their key drivers and enablers, and their impacts, achievements and limitations is presented. A historical review of manufacturing from the point-of-view of the major developments in the market, technology and sciences issues affecting manufacturing is provided. The new requirements for manufacturing are discussed and characteristics of reconfigurable manufacturing systems and their key role in future manufacturing are explained. The paper is concluded with a brief review of specific technologies and research issues related to RMSs.     

Performance evaluation of manufacturing systems: a spreadsheet model

In this paper, we describe the spreadsheet modeling of manufacturing systems which are represented by multi-server and multi-product open networks. The spreadsheet software is characterized by easy data manipulation, on-screen numerical and visual feedback, fast calculation (what-if analysis), and its availability. So far, most spreadsheet models of this type have been used to solve static and deterministic problems in manufacturing systems, ignoring most of the uncertainties. We propose here that a spreadsheet can be implemented for capturing not only static features but also stochastic behaviour of manufacturing systems. The experiments show that the results from the spreadsheet model are reasonably close to those from the other existing approaches. The proposed spreadsheet model could be applied by an engineer to the modeling of manufacturing systems, especially for a first-cut design stage, utilizing his/her own spreadsheet software.     

Nonlinear measures: a new approach to exponential stabilityanalysis for Hopfield-type neural networks

In this paper, a new concept called nonlinear measure is introduced to quantify stability of nonlinear systems in the way similar to the matrix measure for stability of linear systems. Based on the new concept, a novel approach for stability analysis of neural networks is developed. With this approach, a series of new sufficient conditions for global and local exponential stability of Hopfield type neural networks is presented, which generalizes those existing results. By means of the introduced nonlinear measure, the exponential convergence rate of the neural networks to stable equilibrium point is estimated, and, for local stability, the attraction region of the stable equilibrium point is characterized. The developed approach can be generalized to stability analysis of other general nonlinear systems.     

Production control of manufacturing systems: a multiple time scaleapproach

In this note, a stochastic production model containing processes with different time scales is developed. It is shown that if the time scales of the processes are very different, some hierarchical algorithms that are much more efficient than the standard policy iteration method can be developed to find the optimal production control. Moreover, if the time scales fall far apart, the optimal control of a deterministic limiting problem depending only on the mean characteristics of the processes can be used to approximate the optimal control of the original problem. The limiting problem has much lower dimension than its original counterpart and thus is much easier to solve. A numerical example is used to illustrate the potential of the proposed approach     

Flexible manufacturing systems

Flexible manufacturing is an important new technology. The article explains the concept of flexible manufacturing, outlines its worldwide use, and comments on development trends.     

Modelling manufacturing systems

The traditional approach of extrapolating past experience in order to predict the performance of manufacturing facilities has been found to be quite inadequate for automated manufacturing systems. The need to identify the key factors influencing performance has led to the development of both simulation and analytical models to help in design, operation and control. The basic approaches to the development of such models will be outlined and illustrated with examples pertaining to assembly lines, automatic transfer lines, and flexible manufacturing systems. The value of formal models will be demonstrated by examples of the insights which can be gained through their use. The paper will conclude with a discussion of current research needs in both model development and model application.     

Model-based manufacturing integration: A paradigm for virtual manufacturing systems engineering

Current manufacturing system design methodologies produce multiple models of the eventual manufacturing system. These models reflect either the designers view of some subsystem, like materials handling, some level of abstraction, or some developmental stage in the design of the system. These models serve to break the complex system design into smaller, more manageable sized problems. This paper makes a case for the need to integrate these models before the physical system is constructed.     

Modelling manufacturing systems: A birth-death approach

An approximation method for modelling a manufacturing system is introduced. The system is considered as a queueing network, where each queue is limited in size, and interarrival and processing times are exponentially distributed. The birth-death approach is considered and an approximation method to reduce the dimension of the model is developed. The results are the marginal probability distribution of the number of units in each queue; other performance indices, such as mean queue lengths, utilizations of the working stations, and throughput can be easily obtained. The general procedure is applied to model, for example, queues in tandem, a split node, and a more complex network of queues. Simulation and, when possible, comparison with the exact solution show an acceptable error level of the proposed method.     

Appropriate technology for manufacturing: Some management issues

This paper introduces the idea of appropriate technology and applies it to the choices organisations make when designing, implementing and managing advanced manufacturing technologies. Five sets of choices are considered: the type and level of technology; the allocation of functions between humans and machines; the role of humans in advanced systems; the organisation structures to support them; and the ways in which people participate in their design. The paper concludes that most organisations are not effective at developing and implementing appropriate technologies, and that ergonomists have failed to meet the needs of technologies and managers in these areas.     

Designing Holonic manufacturing systems

This paper discusses the design of Holonic manufacturing systems (HMS), with emphasis on manufacturing control. First, it discusses the concept of a Holonic system. Second, it presents the HMS reference architecture for manufacturing control. Third, it addresses the overall design problem, i.e. designing both the holonic control system and the underlying manufacturing system. Finally, the paper addresses the design and development of the control software itself.     

Design and planning problems in flexible manufacturing systems: a critical review

This review paper describes the state-of-the-art research on flexible manufacturing systems (FMS) design and planning issues. The emphasis is on presenting research results coming out of the current FMS literature that help the FMS manager in setting up a highly efficient manufacturing system. In addition to that, it discusses relevant research contributions after 1986, that were not part of any of the previous survey papers on operations research models for FMSs. Also, applications of combinatorial optimization approaches to FMS planning problems are adequately exposed in the paper.