IMPROVING THE REMOTE SCHEDULING OF MANUFACTURING AND INSTALLATION OF LARGE CUSTOM-MADE PRODUCTS Romeo Bandinelli Mauro Iacono Alessandra Orsoni Dipartimento di Energetica “Sergio Stecco” Università di Firenze Via S. Marta 3 50139 Firenze, Italy r.bandinelli@ing.unifi.it Dipartimento di Ingegneria dell’Informazione Seconda Università di Napoli Via Roma 29 81031 Anversa (CE) mauro.iacono@unina2.it School of Business Information Management Kingston University Kingston uponThames Surrey KT2 7LB, UK a.orsoni@kingston.ac.uk KEYWORDS Supply Chain Management, Remote Production Scheduling, HLA Federations, Manufacturing, Railways Switch Point Assemblies. ABSTRACT This paper illustrates the use of statistical inference techniques to improve the scheduling performance of a distributed simulation and scheduling tool based on the XLA-RTI architecture. Specifically, the timing of federation synchronisation events can be customised according to the local failure characteristics of the physical system so as to reduce the necessary delays in information and communications exchange among federates. Ultimately, these improvements can only be beneficial if they have measurable effects on the production performance of the physical system. The paper refers to an industrial application case to measure the production benefits that may be accrued by implementing the proposed methodology. The application context is the manufacturing and installation of railways switch point assemblies, which, to a large extent, are custom-made products in that they come in a multiplicity of assembly types and ultimately need to be customised to fit the specific application requirements. INTRODUCTION The research presented in this paper builds from the outcomes/developments of a project aimed at improving the manufacturing and installation processes of railways switch point assemblies. The original project focused on the activities of an Italian company that produces railways switch point assemblies for the national railway network as well as for industrial users. Part of the assemblies are produced for installation by third parties while others are installed directly by the company’s own installation crew. Earlier studies on the performance of the company’s operations led to the development of an improved HLA federation of simulation and scheduling modules, which reduces the impact of communication delays on scheduling performance, while retaining the benefits of de-coupled scheduling procedures and process control. The initial project involved the development of a simulator to analyse the current performance of the company and search for possible process improvements. An initial set of simulation-based experiments targeted the assessment of a number of performance measures including the percentage of on-time deliveries, resources utilisation, and production lead-times (Gunasekaran, 2001). During the course of the analysis, the drilling and the planning machines were identified as critical because their production rates appeared consistently lower than the others’, thus creating the conditions for potential bottleneck effects. While this observation suggested that an investment might be advisable for the company in order to increase the capacity of these machines, the lack of a structured approach to the scheduling of incoming orders emerged as a critical performance issue. The company, which is relatively young (they have been in the business for approximately two years), had never really invested time and effort in the development of appropriate scheduling policies, and production performance clearly suffered, as reflected by the large percentage of late product deliveries (over 35%). A scheduling tool was then developed and linked to the existing simulation models of the manufacturing and installation processes to test the impact of alternative scheduling policies in relation to the current status of the machines on the shop floor and to the status of the installation process on the designated site (Chang and Maskatsoris, 2001). When the system is used in the loop with the production and installation processes, the first step is to rank the existing orders by due date and estimated production time. Then, based on the progress status of the current production and installation activities, the system decides whether to produce an assembly for third party or for own-crew installation. The additional research presented in the paper refers to the integration of the simulation and scheduling modules into an HLA-RTI federation architecture, which enables the maintenance and update of the modules in separate locations: the scheduling module near the decisional centre and the simulation modules near the production centre. The integration of the modules into a single federation raises important performance issues related to the frequency of communication exchanges among federates (Juhasz et al., 2003; Hwang, 1993). To address these issues the Proceedings 18th European Simulation Multiconference Graham Horton (c) SCS Europe, 2004 ISBN 3-936150-35-4 (book) / ISBN 3-936150-36-2 (CD)