Performance evaluation of WIP-controlled line production systems with constant processing times

• We consider WIP-controlled line production systems with constant processing times.
• For a given QoS, both CONWIP and DBR outperform a Kanban.
• A DBR system needs less buffer capacity than or at most equal a CONWIP system.
• In general, a CONWIP system outperforms a DBR system under the same QoS.
• Under the certain condition a DBR system outperforms a CONWIP system.

We compared three types of WIP-controlled line production systems with constant processing times such as Kanban, CONWIP (constant work-in-process) and DBR (drum-buffer-rope). Based on the observation that such WIP-controlled line production systems are equivalent to m-node tandem queues with finite buffers under communication blocking policy, we applied a max-plus algebra based solution method for the tandem queue to evaluate their performance. Within our knowledge, this research is the first attempt to apply an exact solution method for comparing all three WIP-controlled line production systems at a time. Six-node numerical examples were also used to demonstrate the proposed analysis. The numerical results can be generalized and also provide some insights in designing production systems under certain limited condition.