A new look at the bowl phenomenon

An interesting empirical result in the assembly line literature states that slightly unbalanced assembly lines (in the format of a bowl - with central stations less loaded than the external ones) present higher throughputs than perfectly balanced ones. This effect is known as the bowl phenomenon. In this study, we analyze the presence of this phenomenon in assembly lines with heterogeneous workers (most of them, workers with disabilities). For this purpose, we modify an existing model for the assembly line worker assignment and balancing problem in order to generate configurations exhibiting the desired format. These configurations are implemented in a stochastic simulation model and the obtained results are analyzed. The findings obtained here confirm the existence of the bowl phenomenon in such situations and contributes to deepen our knowledge in this empirical phenomenon.