Sunday, June 30, 2013


Industrial engineering the Toyota Production System - Summary

Denis R. Towill, (2010) "Industrial engineering the Toyota Production System", Journal of Management History, Vol. 16 Iss: 3, pp.327 - 345

 The paper is intended to highlight the undervalued industrial engineering contribution of the Gilbreths to the Toyota Production System. Typical of all innovative engineering projects, TPS brings together, sifts, and successfully adapts ideas from many sources. Critically, TPS is manifestly a system, in which case the totality is (much) greater than the sum of the constituent parts. Furthermore effective linking of the latter is critical in enabling improved throughput. The viewpoint here is that the Toyota Production System is an evolutionary output with some of its roots clearly traceable back to method study combining multiple flows together with more informed design principles and control strategies. The quality movement helped to enable what was ordered to actually become useful goods (as distinct from making scrap). There are three traceable pathways connecting method study and TPS, which were pursued in paper. These include the Japanese Management Association activities; the lecture activities of Lillian Gilbreth and her associates; and  the Scientific Management Movement and FW Taylor.

              Other related topics include the contributions of the quality movement, JIT designers, and the industrial engineering viewpoint of Shigeo Shingo (1989). The cultural implications of successful TPS implementation compared to earlier industrial relations problems are also exemplified in the paper. An important adjunct is the positing of “contemporary” industrial engineering.

However, the  author is apparently still anchored in the “traditional” IE more reminiscent of the inter-war years. Simple vision for TPS – the achievement of continuous material flows. We also examine the “systems” context of TPS operation which ensures the whole is greater than the sum of the constituent parts.

 Continuous material flow

                Crystal Hall project in UK has many features of TPS. Important contributions to the future of logistics and mass production were undoubtedly made in the execution of this massive project. The real innovation was in the process of producing the components, delivering them to the site, and putting them together. Wilkinson (2000) thus comments:

                The exhibition hall was not built. It was assembled. The various parts (including cast-iron columns, wrought iron beams, wooden components, and glass were made all over the UK and delivered directly to the exhibition site by train. They arrived more or less ready for use, and at the right time and were taken straight to the place where they were needed.  From the supermarket we got the idea of viewing the earlier process in a production line as a kind of store. The later process (customer) goes to the earlier process (supermarket) to acquire the needed parts (commodities) at the time and in the quantity needed. The earlier process immediately produces the quantity just taken (re-stocking the shelves). To achieve this in Toyota, Ohno had to make many major changes to production operations. Because the supermarket logistics were designed to replenish only what had just been taken in a timely manner, lot sizes had to be drastically reduced. Hence, the Single-Minute Exchange of Dies (SMED) initiatives (Shingo, 1989). To achieve the efficiencies needed, Ohno and his Toyota colleagues engineered many creative ways to reduce such changeovers. 


Holistic view of TPS

        In their seminal paper, Spear and Bowen (1999) argue that to unravel the DNA of TPS the key factor to understand is that the (surprisingly) rigid specification is the very thing that makes the flexibility and creativity possible. That conclusion was reached by Spear and Bowen (1999) based on an extensive four-year study of the Toyota Production System. They examined the inner workings of more than 40 plants in the USA, Europe, and Japan, some successfully operating the system, but some were not. These authors studied artifacts produced in both continuous process  and discrete manufacturing companies. Products ranged from prefabricated housing, auto parts and final auto assembly, cell phones, and computer printers through to injection-moulded plastics and aluminium extrusions. They studied not only routine production work but also service functions such as equipment maintenance, workers’ training and supervision, logistics and materials handling, and process design and redesign.

 The Gilbreth's “four step” approach

(1) To define the current situation noting anything that could have any possible effect on the job and its performance.
(2) To analyse the job using the special equipment he had either invented or adapted for use for this purpose and supported by one of the several systems of analysis that he had also developed.
(3) To examine the results of these analyses, cutting out any part of the job he found unnecessary, combining different parts where possible and, if practicable, designing equipment that would reduce still further the motions to do the job.
(4) Taking what was left of the job to synthesise this into a new job method which was, to him, the best way the job could be done in the given situation.

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