Investigation into the nature of productivity gains observed during the Airplane Game lean simulation

Investigation into the nature of productivity gains observed during the Airplane Game lean simulation

2012

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DOI: https://doi.org/10.60164/h9b6h8g0c

Authors: Zofia K. Rybkowski, Xun Zhou, Sarel Lavy, Jose Fernández-Solís

Citation:

Rybkowski, Z., Zhou, X., Lavy, S., & Fernández-Solís, J. (2012). Investigation into the nature of productivity gains observed during the Airplane Game lean simulation. Lean Construction Journal, 2012, pp 78-90.

Abstract:

Research Question: What is the nature of productivity gains observed during live playing of the lean simulation, the “airplane game”?

Purpose: The purpose of this research is to investigate and identify the nature of productivity gains observed during live playing of the lean simulation, the airplane game. The intent is two-fold: (1) to identify the specific mechanistic impact of each lean principle, as it is successively introduced; and (2) to identify the productivity contributions of non-mechanistic phenomena such as learning curve and/or Hawthorne Effect. The game serves as a proxy for controlled experimentation in the field—experimentation that is difficult to conduct on actual construction projects but that is important when making claims regarding generalizability of results.

Research Method: To identify the specific mechanistic impact of each lean principle, researchers used Microsoft Excel to graphically map the airplane simulation, stationby-station and second-by-second. Metrics such as time to first batch, number of successful planes and work-in-process were derived from the Excel graphic and evaluated after each round to understand the specific impact of each successivelyintroduced lean principle. To identify the specific impact of non-mechanistic processes on productivity (such as learning curve and Hawthorne effect), researchers compared average results from live playings against results derived from the Excel graphic.

Findings: Comparison of results obtained from the Excel graphic demonstrate the following: (1) reducing batch sizes primarily results in reduced time to first batch; transitioning from a push to pull system primarily results in reduction of work-inprocess; and transitioning from an uneven loading of work to a work-leveled system primarily results in an increased amount of final product; and (2) the contribution of productivity gains from non-mechanistic phenomena such as learning curve and/or Hawthorne effect is relatively minor (i.e. approximately 70% of productivity gains in time to first batch can be attributable to the mechanistic benefits from the four tested lean principles; 30% can be attributed to non-mechanistic phenomena).

Limitations: We chose a deterministic model to enhance clarity. However, a stochastic simulation would have better represented time distributions observed in reality. Implications: Our results are intended to help lean researchers and participants understand the nature of productivity gains observed during live playing of the lean simulation, the “airplane game.” They are also intended to give lean practitioners the assurance that, if performed correctly, introduction of lean principles on a construction project will produce productivity gains.

Value for practitioners: This paper is intended to address some common concerns from players and to help inform those who administer the game.

Keywords: lean principles, skepticism, airplane game, simulation, eureka moment, learning curve, Hawthorne Effect, controlled experimentation