Developing a specific predetermined time study approach: an empirical study in a car industry

Abstract

Determining accurate assembly cycle times in the car industry is an integral part of efficient production, human and facility planning. Three types of methods are available for determining cycle time for manual processes, including: estimating methods, direct observation method (stopwatch), and predetermined motion time systems (PMTSs). Estimating methods cannot determine accurate times. The direct observation method cannot be used for non-existent stations; in addition, this method is very tedious. Although PMTSs are able to properly determine assembly cycle times, some problems have decreased their usage. This paper presents the results of a project accomplished in the Iran-Khodro Car Company (IKCO), the most famous vehicle manufacturing factory in Iran and the Middle East. A particular predetermined time study approach is developed in this company which covers all body shop operations. Besides, some special time tables are developed by the combination of MOST and work time table standards. Finally, an easy-to-use worksheet is designed which can be filled out by moderately educated practitioners. The potential errors will be minimised in the proposed approach to compare with existing ordinary methods.

Keywords:

• time study
• predetermined motion time systems
• cycle time

Acknowledgements

We would like to express our appreciation to the University of Tehran (Grant Number 8108023/1/04) for the financial support for this study. We also would like to acknowledge the helpful assistance and co-operation offered by different managers of IKCO and the kind co-operation of Mr Mohammad Behashti and Miss Farzaneh Aslibeigi from IKCO and also Mr Sadegh Sangari and Miss Shahrzad Faghih Roohi from the University of Tehran for their helpful co-operation.