Manufacturing execution systems

Abstract

The term Manufacturing Execution Systems (MES) was created in 1990 by Advanced Manufacturing Research (AMR) to describe the suite of software products which enables the execution of manufacturing through the integration of planning and control systems. The purpose of this dissertation is to determine the current status of MES and to investigate the possible role of the Industrial Engineer in the development, implementation and use of MES. To achieve this objective, the most commonly accepted, recent and relevant definitions, business models, functions and developments of MES are investigated. Based on these, a new MES Function Matrix is developed and validated by a case study. Finally, Industrial Engineering is related to MES and the role of the Industrial Engineer promoted. The emergence of MES is a result of the evolution of three interrelated elements, namely manufacturing strategies, manufacturing planning and control systems and information technology. The development of global markets and the requirement for agile manufacturing led to the need for MES. The evolution of various aspects of Enterprise Resource Planning (ERP), and more specifically Manufacturing Planning and Control (MPC) systems, is discussed as part of the investigation of the development of MES. The Three-Layer-model and REPAC-¬model by AMR Research, as well as variations of these models compiled by MESA ("International MES Association"), are investigated. Manufacturing execution is absent in traditional MPC models. Modern models, such as the Three-Layer-model, suggest an execution layer to be inserted between the planning and control layers. The investigation of the function models of McClellan and MESA International indicates that discrepancies exist between these models with regard to the functions of MES. A new MES Function Matrix is developed to address such shortcomings and is applied to a case study of DIAMES, a software product used by Aberdare Cables and promoted as an MES product. As an MES developer, the Industrial Engineer can act as designer, planner and innovator. The greatest value can, however, be added by the Industrial Engineer as integrator to ensure that horizontal plant-wide execution takes place, and not only vertical "islands of automation" integrated with planning systems. In order to accomplish this, the Industrial Engineer needs to fulfill the roles of boundary-spanner, facilitator, coordinator, analyst, chairperson, decision-maker, as well as trainer or educator. MES can also be used by the Industrial Engineer as a tool, for example as part of a program of continuous improvement. The identification of the relationship between the expertise of the Industrial Engineer and the roles to be played within the MES arena gave birth to the establishment of an MES research initiative at the Department of Industrial and Systems Engineering of the University of Pretoria.