244 Int. J. Modelling, Identification and Control, Vol. 12, No. 3, 2011 Copyright © 2011 Inderscience Enterprises Ltd. Identifying parameters of a broaching design using non-linear optimisation Ertunga C. Özelkan* Systems Engineering and Engineering Management, and Center for Lean Logistics and Engineered Systems, The University of North Carolina at Charlotte, Charlotte, NC 28223, USA E-mail: ecozelka@uncc.edu *Corresponding author Özkan Öztürk Department of Mechanical Engineering and Center for Precision Metrology, The University of North Carolina at Charlotte, Charlotte, NC 28223, USA E-mail: oozturk@uncc.edu Erhan Budak Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli, Tuzla, Istanbul, 34956 Turkey E-mail: ebudak@sabanciuniv.edu Abstract: Broaching is one of the most recognised machining processes that can yield high productivity and high quality when applied properly. One big disadvantage of broaching is that all process parameters, except cutting speed, are built into the broaching tools. Therefore, it is not possible to modify the cutting conditions during the process once the tool is manufactured. Optimal design of broaching tools has a significant impact to increase the productivity and to obtain high quality products. In this paper, an optimisation model for broaching design is presented. The model results in a non-linear non-convex optimisation problem. Analysis of the model structure indicates that the model can be decomposed into smaller problems. The model is applied to a turbine disc broaching problem which is considered as one of the most complex broaching operations. Keywords: broaching; machining optimisation; turbine disc broaching. Reference to this paper should be made as follows: Özelkan, E.C., Öztürk, Ö. and Budak, E. (2011) ‘Identifying parameters of a broaching design using non-linear optimisation’, Int. J. Modelling, Identification and Control, Vol. 12, No. 3, pp.244–252. Biographical notes: Ertunga C. Özelkan is an Assistant Professor of Engineering Management and Associate Director of the Center for Lean Logistics and Engineered Systems at the University of North Carolina at Charlotte. He received his PhD in Systems and Industrial Engineering from the University of Arizona. His research is on systems optimisation, decision analysis, supply chain management and lean production planning. Özkan Öztürk is a PhD candidate at the Mechanical Engineering Department at University of North Carolina at Charlotte. His research interests are analysis and modelling of machine tools, precision instrument design and metrology. Erhan Budak is an Associate Professor of Engineering at the Faculty of Engineering and Natural Sciences at the Sabanci University. He received his PhD in Mechanical Engineering from the University of British Columbia. Some of his research interests are high productivity machining, analysis and modelling of machine tools, and design for manufacturing.