The purpose of this paper is to investigate the performance of unpaced unreliable production lines that are deliberately unbalanced in terms of their coefficients of variation (CVs).
A series of simulation experiments were carried out for five and eight station lines with mean buffer space set at one, two, four and six units. CVs were allocated in 12 different configurations for each of these lines.
The results show that the best unbalanced CV patterns in terms of throughput rates or idle times as compared to a balanced line counterpart are those where the steadiest stations are concentrated near the centre of the line. On the other hand, either concentrating the steadier operators towards the centre or close to the end of the line gives best average buffer level results.
The results provide guidelines for production line managers when designing unpaced unbalanced lines depending on their performance aims.
The investigation of the effects of unbalancing CVs in unreliable lines has not previously been studied and can provide insights into how best to place workstations with differing variability along the line.
