Takting the Parade of Trades: Use of Capacity Buffers to Gain Work Flow Reliability

The Parade of Trades game introduces concepts of sequential dependence and process variability in order to illustrate the detrimental impact such variability has on a system’s performance. In this paper we refer to the Parade of Trades to explore the use of capacity buffers in order to improve system performance as is done, for example, when developing a takt plan. Using discrete-event simulation as a discovery tool to study alternative means of work structuring, we here present an augmented Parade of Trades model in which standby capacity is available to make up for any insufficiency in completing work relative to what needs to be completed in any given takt. The judicious provision of standby capacity can help to gain work flow reliability. The design of production systems using standby capacity is barely mentioned in the construction literature. We start to shed light on this design question in this paper. The discussion of the model’s results expands on the distinction between using standby capacity vs. outright adding capacity. This distinction is important to understand in the context of work flow reliability as well as continuous improvement based on Lean thinking, and should spark good follow-on discussion!