Int. J. Industrial and Systems Engineering, Vol. 4, No. 2, 2009 Assembly features: definition, classification, and usefulness in sequence planning Hamid Ullah* Erik Bohez Design and Manufacturing Engineering, School of Engineering and Technology, Asian Institute of Technology, Pathumthani 12120, Thailand. Email: hamidullah@nwfpuet.edu.pk , Email: bohez@ait.ac.th *Corresponding author M. A. Irfan NWFP University of Engineering & Technology, Peshawar, Pakistan. E-mail: mairfan@brain.net.pk Abstract: Unique definition and classification of assembly feature are presented. Assembly feature’s definition is provided using the concept of assembly intents. Assembly features classification is done based on useful assembly-specific information. Assembly features provide information that result in a smaller number of assembly sequences that have to be checked in assembly sequence optimization. Due to the reduction in assembly sequences, AND/OR graph not only reduces considerably but also becomes very simple. This can result in a significant reduction in the computation time for assembly sequence planning. Real-life examples are given to demonstrate how assembly features are useful in sequence planning. Keywords: Assembly feature (AF); Assembly intents ( ); Precedence relationship; Features classification; Assembly sequence planning (ASP); AND/OR graph a I Reference to this paper should be made as follow: Ullah, H., Bohez, E. and Irfan, M.A. (2009) ‘Assembly features: definition, classification, and usefulness in sequence planning’, Int. J. Industrial and Systems Engineering, Vol. 4, No. 2, 2009. 1