A new method for solving buffer allocation problem in large unbalanced production lines

Abstract

Solving the buffer allocation problem (BAP) in long production lines is difficult because it is an NP-hard problem. In this paper, we propose a new approach to solve the BAP for long series-parallel unbalanced production lines with the objective of minimising the average work-in-process subject to a throughput rate constraint. Instead of directly optimising a long line, this method decomposes the original long line into several small decoupled subsystems and adds relation condition variables between the subsystems. After several iterations between subsystem optimisation and condition updating, this method can obtain the optimal or near-optimal solution of the original system with a significantly improved computational efficiency. Extensive numerical experiments demonstrate the accuracy and efficiency of this approach. Finally, several examples and a multi-factorial experimental analysis are provided to show the influence of the decomposition strategy, initial values, and parameters of the target systems on the performance of the proposed method.

Keywords:

• buffer allocation problem
• series-parallel production lines
• unbalanced lines
• decomposition-coordination
• unsaturated supply

Acknowledgements

The authors also thank the three anonymous reviews for their thoughtful comments, which help improve the quality of the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant numbers 51775120, 61573109, 51805096, 61973089]; the program of China Scholarships Council [grant number 201808440438); Natural Science Foundation of Guangdong Province, China [grant number 2018A030313477]; China Postdoctoral Science Foundation funded project [grant number 2018M630929].