Showing 4 results for G. Moslehi
M. Aghdasi, F. Mokhatab Rafiei and G. Moslehi,
Volume 17, Issue 1 (7-1998)
Abstract
This paper presents a summary of the results from the simulation of a given two-stages production system which uses JIT. The system consists of an assembly line with two automated assembly cells and two assembly stock points and one manufacturing cell with three manufacturing stock points for storing reserved parts and one receiving stock. Carts with fixed capacity are used for handling the parts. A kanban is attached to each cart. The minimum number of kandbans required to operate the system without shortage in stock are estimated. The effects of changing the demands mean and its variation on the number of carts are also investigated. Finally, a different simulation model is developed for the same production system using conventional job shop decipline and some main characteristics have been compared to the results, from the first model.
A. Memariani, G. Moslehi,
Volume 17, Issue 1 (7-1998)
Abstract
Flow shop sequencing problem is included in NP-hard problems and a number of heuristic methods have been developed to solve it. Most of these methods are offered for the crisp processing time. However fuzzy algorithm is appropriate for the problems with fuzzy processing time. This paper presents a method in which an algorithm is used to minimize make span of flow shop with fuzzy processing time by taking advantage of fuzzy mathematics. This method is based on the behavior of the decision maker who can make either pessimistic or the most likely decisions. The algorithm includes proper relations and corresponding results.
M. Amin-Nayeri and G. Moslehi,
Volume 19, Issue 1 (7-2000)
Abstract
The problem of determining the sequence of a set of jobs with the objective function of minimizing the maximum earliness and tardiness in one machine is studied.
Production systems like JIT are one of the many applications of the problem. This problem is studied in special cases and their optimal solutions are introduced with simple orders. In general, some effective conditions for neighboring jobs have been developed and the dominant set for the optimal solution is determined. Branch and Bound (BB) method is also used for this problem. The strong upper and lower limits are introduced in BB, resulting in optimal solutions to a lot of problems in short time periods. To show the effectiveness of the suggested solution methods, as many as 720 problems in different sizes, with 5 to 100 jobs, have been randomly generated and solved.
G. Moslehi and M. Mahnam,
Volume 27, Issue 2 (1-2009)
Abstract
While a great portion of the scheduling literature focuses on time-based criteria, the most important goal of management is maximizing the profitability of the firm. In this paper, the net preset value criterion is studied taking account of linear time-dependent cash flows in single machine and flow shop scheduling problems. First, a heuristic method is presented for the single machine scheduling problem with NPV criterion. Second, the permutation flow shop scheduling problem is studied with NPV criterion. An efficient Branch & Bound algorithm is accordingly presented using strong lower and upper bounds and dominace rules which are expanded for this problem. Finally, three heuristic methods are presented and compared to find
appropriate solutions over short periods. By generating random problems of different sizes, it has been shown that the Branch & Bound method is efficient in solving small and medium sized problems, and also that the presented heuristic algorithm is efficient in tackling problems of any size.
