Analysis of a stochastic multistage production line system under CONWIP/Finite buffers control by decomposition
- Bangkok : Asian Institute of Technology, 1997
- 73 p.
- Thesis ; no. ISE-97-30 .
- Asian Institute of Technology. Thesis ; no. ISE-97-30 .
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Advanced Technologies
Thesis (M.Eng.) - Asian Institute of Technology, 1997
In recent times, there is a great pressure on production line to have minimum total inventory for getting more benefits. Some years after the success of Toyota Motor Co. applying Kanban system, a new effort to go to a lean production line is proposed, i.e. CONWIP. CONWIP sets the total inventory in constant level. However, the CONWIP assumes that the capacity of the buffers are unlimited. It is not possible in the real production line. This study is trying to observe what will happen if the CONWIP control is combined with the (TOYOTA) kanban control on a multistage production line. The idea was firstly proposed by Bonvik (I 996). In this paper, just a simple way is conducted to get the solution. Two algorithms, i.e. Frein-Commault-Dallery's algorithm for close-line system and Di Mascolo David-Dallery's algorithm for assembly/disassembly system, are combined to a new algorithm to analyze the performance of a CONWIP/Finite buffers controlled production line. This method is simple because it only uses the two-machine line formula as the basic analytical calculation in the decomposition analysis. By adding some more approximations for numerical calculating needs, the results are satisfying (with error less than 10%) compared with simulation results for less reliable production line. It means that approximating numerically the reliability of Machine S is in fact not sufficient for more/very reliable line. Anyway, an analysis of the CONWIP/Finite buffers control is conducted, though limited to this less reliable line. Hence some conclusions can be noted based on this simple numerical calculation method.