In this paper we discuss the concept and design criteria for a framework that facilitates the performance assessment of shop-floor control systems. Our basic concept includes a simulation model that emulates the shop-floor of a wafer fab, sends information to the control system, and receives information back from the control system. The shop-floor control system is realized as a separate module...

Flexible job-shop scheduling problem derived from the job-shop scheduling problem, and is more realistic than the job-shop scheduling problem in the manufacturing enterprise. It should be utilized with high efficiency. But it is a multi-objective optimal problem. Three minimization objectives (Maximum completion time (makespan), Total workload of machines and Workload of the critical machine) a...

We combine genetic algorithms and case-based reasoning principles to nd optimally directed solutions to open shop scheduling and open shop rescheduling problems. Appropriate solutions to open shop scheduling problems are injected into the genetic algorithm's population to speed up and augment genetic search on a related open shop rescheduling problem. Preliminary results indicate that the combi...

Flexible job shop scheduling problem, is an extension of the classical job shop scheduling problem. In Flexible job shop scheduling problem, there are more than one machine with the same features for the same purpose. The problem can be defined as appointing the jobs to the machines (assignment) and ordering the jobs at each machine (sequencing) to serve the desired purpose. Multi-objective fle...

In this paper, mathematical models for permutation flow shop scheduling and job shop scheduling problems are proposed. The first problem is based on a mixed integer programming model. As the problem is NP-complete, this model can only be used for smaller instances where an optimal solution can be computed. For large instances, another model is proposed which is suitable for solving the problem ...

A discrete event simulation model was developed to study the flow of material and product in a shop floor. It uses real time data available from a job shop sole dedicated to noncommercial contracts and as such deals with very seasonal demand. The objective of this model is to provide the shop with a decision support tool that will assist in evaluating the movement of products throughout the sho...

In this paper, a new approach to overlapping operations in job shop scheduling is presented. In many job shops, a customer demand can be met in more than one way for each job, where demand determines the quantity of each finished job ordered by a customer. In each job, embedded operations can be performed due to overlapping considerations in which each operation may be overlapped with the other...

A frequently occurring operational problem is one of processing a given number of jobs (commodities) on a specified number of machines (facilities) referred to by various investigators as scheduling, dispatching, sequencing, or combinations thereof (Gupta and Stafford, 2006). In most manufacturing environments, a set of processes is needed to be serially performed in several stages before a job...

This paper presents the application of self organinsing migration algorithm (SOMA) to the scheduling problem of flow shop. Flow shop is regarded as the most widely utilized shop management system. Two different benchmark problems are attempted with good results obatined both in comparison with the optimal and other published heuristics. INTRODUCTION Advanced manufacturing systems often rely on ...