Regular Article Design of a STEP compliant system for turning operations Yusri Yusof a,n , Keith Case b,1 a Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia Johor (UTHM), Parit Raja, 86400 Batu Pahat, Johor, Malaysia b School of Mechanical Engineering, Loughborough University, Loughborough LE11 3TU, United Kingdom article info Article history: Received 15 September 2008 Received in revised form 2 May 2010 Accepted 4 May 2010 Available online 7 June 2010 Keywords: STEP-NC ISO 14649 ISO 10303 CAD/CAPP/CAM Turning CNC abstract The changing economic climate has made global manufacturing a growing necessity over the last decade, forcing companies from East and West to collaborate beyond geographic boundaries in the design, manufacture and assembly of products. The ISO 10303 and ISO 14649 Standards (STEP and STEP-NC) have been developed to introduce interoperability into manufacturing enterprises so as to meet the challenges of responding to production on demand. This paper describes and illustrates a STEP compliant CAD/CAPP/CAM System for the manufacture of rotational parts on CNC turning centers. The information models to support the proposed system together with the data models defined in the ISO 14649 standard used to create the NC programs are also described. A structured view of a STEP compliant CAD/CAPP/CAM system framework supporting the next generation of intelligent CNC controllers for turn/mill component manufacture is provided. Finally a proposed computational environment for a STEP-NC compliant system for turning operations (SCSTO) is described. SCSTO is the experimental aspect of the research and is supported by information models that and have been constructed using a structured methodology and object-oriented methods. SCSTO was developed to generate a Part 21 file based on machining features to support the interactive generation of process plans utilizing feature extraction. A case study component has been developed to prove the concept of using the milling and turning parts of ISO 14649 to provide a turn-mill CAD/CAPP/CAM environment. & 2010 Elsevier Ltd. All rights reserved. 1. Introduction Today, with the use of computer and communication technol- ogies in manufacturing industry, manual and semi-automatic methods have largely being replaced by computer aided design (CAD) and computer aided manufacturing (CAM) to implement concurrent engineering [1]. Widespread CADCAM systems with reduced human interaction should result in increased production, reduced costs and better quality of product. Modern CNC machines utilize a variety of cutting technologies including multi-turrets and multi-spindles in various axial configurations increasing the level of complexity compared with machines of previous decades [2]. A large number of CAx systems have been developed and implemented in recent years to provide computer support to many stages of product life and many of these can simulate virtual CNC machining with the complete machine toolpath [3]. Most of these systems are specialized to support certain applications and are based on an information model that handles the application specific view of the product. These CAx systems do not share common databases for the product information. Since the first NC machine was introduced in 1947, various process planning packages have been developed and each new system attempted to interpret the part data more reliably. To date there are more than 2000 varieties of CNC machine-controller combinations around the globe, leading to the need for a single standard to improve productivity by increasing the richness of interactions and transactions. An initial standard is ISO 10303, informally known as the STandard for the Exchange of Product (STEP) data, which aims to provide a single International Standard for all technical aspects of products [4]. This paper presents an overall review of the various research projects carried out by the major research groups in this area. The relevant research issues for the development and introduction of reconfigurable machines tools are presented focused on turning operations. Finally, the authors propose a STEP-NC compliant CAD/CAPP/CAM system that is currently being implemented at Bath University, UK and UTHM, Malaysia. A case study based on a component from industry is used to demonstrate the capabilities of the system. 2. Review of STEP-compliant manufacturing Over the last 15 years many efforts have been made to apply STEP concepts to the data interface between CAD/CAM and CNC. Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rcim Robotics and Computer-Integrated Manufacturing 0736-5845/$ - see front matter & 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.rcim.2010.05.002 n Corresponding author. Tel.: + 607 4537701; fax: + 607 4536080. E-mail addresses: yusri@uthm.edu.my (Y. Yusof), k.case@lboro.ac.uk (K. Case). 1 Tel.: + 44 1509 227654. Robotics and Computer-Integrated Manufacturing 26 (2010) 753–758