A Case Study Measuring the Impact of a Participatory Design Intervention on System Complexity and Cycle Time in an Assemble-to-Order System

Abstract

The literature identifies that a better understanding of the relationship between people and complexity in assembly design and operation is needed. This need is studied here with an industrial case study and by employing a socio-technical approach: assembly system operators are invited to take an active role in the participatory design of an assemble-to-order system. To measure the impact of the design intervention, a before versus after comparison is made. The investigative process begins with 371 observation samples; elementary units of the cycle time population are tested with Welch's ANOVA and regression into complexity variables and a complexity ratio. The complexity ratio is correlated to cycle time with regression (R-sq>0.75, 95% confidence), highlighting improved complexity organization with the “after” working design strategy. The observation models are used to predict theoretical complexity ratios and cycle times for direct comparison with a paired t-test. In the case study, the participatory design intervention proves significant by decreasing mean cycle time by 0.72min/assembly. Based on these results, the investigative process proves useful in assessing assembly system complexity relative to a working design (complexity ratio) and mean cycle time.