System-theoretic properties of the process of continuous improvement in production systems

The process of continuous improvement in serial production lines with unreliable machines and finite buffers is considered. It is shown that in a well designed system each buffer is, on the average, half full, and each machine has equal frequencies of blockages and starvations. These are referred to as indicators of improvability. If the indicators are not satisfied, the system can be improved by either work-in-process and workforce redistribution or bottleneck elimination, or both. Guidelines for carrying out the process of continuous improvement are formulated.