International Journal of Engineering, Science and Technology Vol. 2, No. 11, 2010, pp. 90-103
INTERNATIONAL JOURNAL OF ENGINEERING, SCIENCE AND TECHNOLOGY www.ijest-ng.com © 2010 MultiCraft Limited. All rights reserved
Implementation of an online scheduling support system in a high mix manufacturing firm L. Siva Rama Krishna1*, V. Mahesh2, Sandeep Dulluri 3, C. S. P. Rao4 1*
Department of Mechanical Engineering, University College of Engineering ,Osmania University, Hyderabad, INDIA 2 Department of Mechanical Engineering, S.R. Engineering College, Warangal INDIA 3 Enterprise functional architect, JDA Software, Hyderabad, INDIA 4 Department of Mechanical Engineering, National Institute of Technology, Warangal,INDIA * Corresponding Author: e-mail: firstname.lastname@example.org, Tel +91-40-40135931
Abstract Scheduling is an important decision making processes in any manufacturing industry. One of the key objectives of scheduling is minimizing the makespan. Generating the best job shop schedule with the makespan criterion for a multi-product manufacturing industry in a reasonable time remains a challenging task, due to its NP hard nature. In this context, this paper discusses the implementation of an online scheduling support system for a high mix manufacturing firm. The firm is a worldclass leader in turbine manufacturing, based in India. The production planning and control (PPC) department of firm has to schedule the jobs, on the available special purpose machines (SPMs), respecting the capacity constraints and most importantly the priority of work orders. The system is developed in two phases. The first phase involves the development of a scheduling support system. A priority based heuristic for minimizing the makespan is presented. The heuristic considers a host of real world issues, like resource breakdown, utilization, recirculation of the jobs on the machines etc. The crux of this paper is to present an approach to smoothen the work loads viz., under loads and over loads, that occur on various machines due to the lack of integration between capacity planning and generated schedule. The second phase involves integrating it with World Wide Web (WWW) which allows the decision makers with the flexibility of distributed decision making. Keywords: Job shop scheduling, makespan, capacity planning, World Wide Web (WWW) 1. Introduction This paper is intended to discuss a job shop scheduling problem from the perspective of a high mix manufacturing firm under investigation. The firm is a world-class leader in turbine manufacturing, based in India. The production planning and control (PPC) department of firm has to schedule the jobs, on the available special purpose machines (SPMs), respecting the capacity constraints and most importantly the priority of work orders. From the time a customer places an order for a particular turbine the order is uniquely identified and all the parts regarding the turbine (product) are also identified. The firm manufactures several types of turbines (steam, gas), besides compressors and generators. To summarize, the firm is a complex job-shop, which is capable of manufacturing host of products with a wide scope in variety. A large variety of constraints and relaxations must be added to classical job shop scheduling problem (JSSP) in order to represent real production environments. The number and type of constraints depend on the environment under consideration. It is impractical to design a universal scheduling system that considers all the characteristics of every production environments. Nevertheless, some constraints and alternatives have a high frequency of occurrence in real job shop environments. A scheduling system which models these commonly encountered characteristics would be able to solve the absolute majority of industrial job shop scheduling problems that rise in practice. This paper includes the following characteristics in a relevant subset of real constraints and...