Planning of synchronized assembly lines taking into consideration human performance fluctuations

Abstract

Increasing demands on the flexibility of assembly workers has led to numerous times of high exposure rates within one workday. Inflexible processing times in synchronized assembly lines mismatch the individual, circadian variable work capacities of operators. As a result, frequent performance peaks due to limited possibilities for individualization elevate physiological and psychological workloads. This paper’s main objective is an individualization of assembly system performance requirements aimed at providing the opportunity to adapt current processing times to individual work capacities for reactively levelling the operators’ workload. On the one hand, the authors focus on defining requirements to enable a company to record valid current processing times within a synchronized assembly line. The authors provide a checklist aimed at generating sets of raw data specifying the necessary requirements. This checklist can be applied by the user of the approach. The authors provide an approach of statistical data processing to eliminate non-valid data-sets which do not allow inference on human performance fluctuations. On the other hand, the paper provides an approach for planning synchronized assembly lines taking into consideration human performance fluctuations. Based on defining performance and time characteristics, the authors methodically deduce one exemplary recommendation for the examined synchronized assembly lines quantifying the expected value for production periods. As a result, this combination leads to the possibility of methodically adapting systems’ performance requirements to fluctuating operators’ work capacity. Moreover, application of the presented approaches within a field study leads to an analysis and evaluation of significant production periods in a German car manufacturer’s engine assembly.