Unnecessary Overtime as the Component of Time Loss Measures in Assembly Processes

Z. Ebrahim, A. H. A. Rasib


Hidden Time Loss (HTL) occurs along the production processes that have a significant effect on productivity. Overall Equipment Efficiency (OEE) is the most popular performance measurement tool used in the production line. Equipment performance is one of the measure components of OEE that caters HTL. However, OEE doesn’t really fit in measuring operation performance of assembly process especially the semi-auto assembly and the manual assembly process. There would be the amount of HTL have occurred along the semi-auto assembly and manual assembly processes that become critical when to involve high product variety at the same production line. Thus, the purpose of this paper is to introduce the Unnecessary Overtime (UOT) as one of the component of Time Loss Measures (TLM) in assembly processes. The structure of UOT is developed through a thorough literature study on manufacturing operations and its performance measures. The UOT structure is validated by using case study at five automotive manufacturing companies. The results show that the UOT is one of the components of TLM in semi-auto and manual assembly processes.

Full Text:



E. Nazarian, J. Ko, and H. Wang, "Design of multi-product manufacturing lines with the consideration of product change dependent inter-task times, reduced changeover and machine flexibility," Journal of Manufacturing Systems, vol. 29, pp. 35–46, 2010.

U. Dombrowski, T. Mielke, and C. Engel, "Knowledge management in lean production systems.," Procedia CIRP 3, pp. 436 – 441, 2012.

O. Battaia, X. Delorme, A. Dolgui, A. Hagemann, S. Kovalev, and S. Malyutin, "Workforce minimization for a mixed-model assembly line in the automotive industry," International Journal of Production Economics, 2015.

T. A. Boyle, “Towards best management practices for implementing manufacturing flexibility,” Journal of Manufacturing Technology Management, vol. 17, no. 1, pp. 6-21, 2006.

K. J. Klassen, and T. R. Rohleder, “Demand and capacity management decisions in services: How they impact on one another,” International Journal of Operations and Production Management, vol. 22, no. 5, pp. 527-548, 2002.

Y. F. Hung, C. C. Huang, and Y. Yeh, “Real-time capacity requirement planning for make-to-order manufacturing with variable time-window orders,” Computers and Industrial Engineering, vol. 64, no. 2, pp. 641-652, 2013.

M. Smith, and S. Zagelmeyer, “Working time management and SME performance in Europe,” International Journal of Manpower, vol. 31, no. 4, pp. 392-409, 2010.

K. Mathur, and G. A. Suer, “Math modeling and GA approach to simultaneously make overtime decisions, load cells and sequence products,” Computers & Industrial Engineering, vol. 66, no. 3, pp. 614-624, 2013.

M. Kemal Karasu, M. Cakmakci, M. B. Cakiroglu, E. Ayva, and N. Demirel-Ortabas, “Improvement of changeover times via Taguchi empowered SMED/case study on injection molding production,” Measurement, vol. 47, pp. 741-748, 2014.

K. Fukuyama, T. Kawabata, and J. Na, “Conflict analysis on the enforced-move-by-majority rule in a group decision making situation,” IEEE Proc. of the Int. Conf. on Systems, Man, and Cybernetics. PP. 2031 – 2036, 2013.

D. J. Johnson, “A framework for reducing manufacturing throughput time,” Journal of Manufacturing Systems, vol. 22, no. 4, pp. 283-298, 2003.

S. G. Li, and Y. L. Rong, “The reliable design of one-piece flow production system using fuzzy ant colony optimization,” Computers and Operations Research, vol. 36, no. 5, pp. 1656-1663, 2009.

© Journal of Advanced Manufacturing Technology