FMS Environment Research Articles

Prescriptive Model for Managing and Organising FMS and CIM Environment

Today, we have many organizational models enjoying considerable success within its domain of applicability, but none seems to be appropriate for managing FMS and CIM environment, because they are not structured with flexible mode. In fact, they are lagging behind the strategic requirements of new technology. The model for managing FMS and CIM has to accommodate simultaneously the increasing number of success variables/goals which are often seemingly contradictory and noncom mensurable. Specifying structural properties that facilitate the simultaneous accomplishment of multiple success variables/goals would provide the basis for managing and organizing FMS and CIM environment. This article discusses a few success variables that the new model has to accommodate and the structural properties for their accomplishment. A prototype organizational model is also presented.

Towards Real-Time Visual Part Identification for FMS

Development of a knowledge-based visual part identification system is presented in this paper. It uses the automated knowledge acquisition techniques to construct decision rules for identification. Algorithms have been developed to achieve identification speed and accuracy. It has been proved both theoretically and experimentally that this low-cost visual identification approach is feasible for on-fine identification of a part in an FMS environment.

Simultaneous Scheduling of Machines and Material Handling System in an FMS

This paper is an attempt to make the AGV scheduling an integral part of the overall scheduling activity in an FMS environment. The sequence-dependent nature of travel times for the deadheading trips between successive loaded trips of the AGVs increases the problem difficulty. The problem is decomposed into two subproblems, and an iterative solution procedure is developed where the operation completion times obtained from the machine schedule subproblem by means of an heuristic are used to construct time windows for each material handling trip in the vehicle scheduling subproblem which is handled as a sliding time window problem.

Dynamic load control policies for a flexible manufacturing system with stochastic processing rates

Real-time scheduling and load controls of FMSs are complex processes in which the control logic must consider a broad spectrum of instantaneous state variables while taking into account the probabilistic future impact of each decision at each time epoch. These processes are particularly important in the management of modern FMS environment, since they are known to have a significant impact on the FMS productive capacity and economic viability. In this article we outline the approach developed for dynamic load controls within an FMS producing a variety of glass lenses. Two revenue-influencing objective functions are evaluated for this capital-intensive facility. It is shown that by using Semi-Markovian modeling concepts, the FMS states need to be observed only at certain decision epochs. The mean holding time in each state is then obtained using the probability distribution function of the conditional state occupancy times. Several key performance measures are then derived by means of the value equations. In addition, the structure of the optimal policies are exemplified for a variety of operational parameters. It is shown that the optimal policies tend to generate higher buffer stocks of parts in those work centers having the highest revenue-generation rates. These buffer stocks get smaller and smaller as the relative processing capacity of the centers increases. Similar observations lead us to the introduction of several promising heuristics that capture the structural properties of the optimal policies with a significantly smaller computational effort. Results of the empirical evaluation of these heuristics are also analyzed here.

Simulation study of an AGV system in an FMS environment

A simulation program written in ECSL to simulate an AGV system serving an FMS is presented. It incorporates a special algorithm to enable ‘intelligent’ routing of the AGVs with minimum control requirements. The program was used to examine several parameters and scheduling/control disciplines affecting the AGV system's performance for a specific FMS. Results show that selection of an appropriate combination of parameter values can have a beneficial effect on the FMS.

FMS— Research and industrial development in coordination

This paper describes the problems and possible solutions for interfacing equipment from different vendors. The solutions are to be used in the industrial development program for FMS, sponsored by the National Swedish Board for Technical Development (STU). It also discusses the different demands on interfaces and the division of responsibility in the factory. This discussion is based on a model of the functions in an FMS environment. Suggestions for further work are also given.

A reliability warranty concept for the FMS environment : Donald Kenneth Shelton and Richard G. Paxman. IEEE Proc. Reliab., 34 (1982)

A reliability warranty concept for the FMS environment : Donald Kenneth Shelton and Richard G. Paxman. IEEE Proc. Reliab., 34 (1982)