An effective method to reduce inventory in job shops

Author

Luh, Peter B. ; Zhou, Xiaohui ; Tomastik, Robert N.

Author_Institution

Dept. of Electr. & Syst. Eng., Connecticut Univ., Storrs, CT, USA

Volume

16

Issue

4

fYear

2000

fDate

8/1/2000 12:00:00 AM

Firstpage

420

Lastpage

424

Abstract

Inventory plays a major role in deciding the overall manufacturing costs, and a good scheduling system should balance the on-time delivery of products versus low work-in-progress (WIP) inventory. In this paper, the “constant work-in-process” (CONWIP) concept is applied to job shop scheduling to effectively control WIP inventory. A new mathematical formulation of CONWIP-based job shop scheduling with a separable structure is presented. By using a synergistic combination of Lagrangian relaxation, dynamic programming, and heuristic methods, good schedules are obtained in a reasonable amount of computation time. Results show that the new method can directly control the maximum WIP levels while maintaining good on-time delivery performance

Keywords

computational complexity; dynamic programming; heuristic programming; production control; stock control; CONWIP; Lagrangian relaxation; computation time; constant work-in-process; dynamic programming; heuristic methods; inventory reduction; job shops; low WIP inventory; manufacturing costs; maximum WIP levels; synergy; timely product delivery; Capacity planning; Costs; Job shop scheduling; Lagrangian functions; Manufacturing; Materials requirements planning; Processor scheduling; Production systems; Raw materials; Throughput;

fLanguage

English

Journal_Title

Robotics and Automation, IEEE Transactions on

Publisher

ieee

ISSN

1042-296X

Type

jour

DOI

10.1109/70.864236

Filename

864236