Manufacturing Production Line Modelling and Classification of Associated NP-Hard Problems

Abstract

The purpose and scope of this studyThis study was part of a two-year research project financed by the European Regional Development Fund (ERDF) called Research Services in Manufacturing: ICT in Manufacturing. The objective of this process was to create a software solution that allows operators to model production lines and determine and classify the scheduling problems represented by the model. It has long been felt that not enough information is available regarding the scheduling problems affecting the manufacturing industry in Malta. This project was undertaken to gain additional information on the state of scheduling in the local manufacturing industry and to provide an extensible framework that can be used for current analysis and future research.This study focused on providing a graphical means of representing scheduling problems. This representation describes the abstraction of the production line involved in manufacturing a product. The second aim of the study is to create a set of heuristics using the model to classify the scheduling problem according to its computational complexity, and when possible, pointing to the relevant literature used to derive the classification in order to help researchers understand the problem better.Scheduling involves efficient utilisation of scarce resources. While this study focuses on scheduling in manufacturing industry, Leung draws a parallel to the problems encountered by computer scientists in the 1960s when computational resources (CPU, memory and I/O devices) were scarce [8]. This results of this study are of interest to computer scientists, operators in the manufacturing industry whose work deals with scheduling and to researchers in the field of optimisation. AbstractOptimisation of production lines is known to be NP-Hard in the general case so many near-optimal approximation algorithms have been researched to overcome the challenge [1]. In this paper we describe an approach to modelling production lines using a graph theoretic model. In particular, we focus on single machine and job shop problems. We show that the model can be extended to open shop problems. We also discuss how the model can be used to classify scheduling problems from the generated models. Int J Comput Softw EngIJCSE, an open access journal