چکیده:
The fundamental function of a Cellular Manufacturing System (CMS) is based on definition and recognition of a type of similarity among the parts that must be produced in a planning period. Cell Formation (CF) and cell machine layout design are two important steps in implementation of the CMS. This paper represents a new mathematical nonlinear programming model for dynamic cell formation that employs the rectilinear distance notion to determine the layout in the continuous space. In the presented model, the objective function accurately calculates the costs of inter and intra-cell movements of parts and calculates the cost of a cell restructure. Due to the problem complexity, the presented mathematical model is categorized in NP-hardness; thus, a Genetic Algorithm (GA) is used for solving this problem. Comparing the results from the GA and the results from solving a linear model through Lingo specifies that solving the presented model accurately for more than four machines in a logical time is impossible.
خلاصه ماشینی:
"Literature review Studies conducted in dynamic cell formation can be categorized as follows: Studies that propose appropriate models in cellular manufacturing systems with respect to production information, and solve the model employing accurate or heuristic algorithms.
In his study, he considered a number of assumptions, such as multiple operational paths, batch movements of the parts, variable production costs, machine time capacity constraints, lower and upper bounds for cells capacity, number of cell constraint, demand variations, machine purchasing costs, cell restructuring cost, inter-cell relocating cost and multi-task machines.
Safaei and Tavakkoli-Moghaddam [11] developed a new model for solving the dynamic cell formation problem considering subcontracting with some assumptions, such as batch movement of the parts, inter-cell relocating, demand variations in different periods, machine time capacity, maximum capacity of cells, existence of multitask machines and parts returns by purchasers.
[15] proposed multi-criteria linear-integer model that includes information, such as cell capacity constraints, inter-cell relocation, multi operational paths, machines reestablishment in planning periods, existence of several single type machines and operation sequence.
They solved the proposed model employing a Scatter Search (SS) algorithm and demonstrated that for this problem, the SS Reviewing the previous studies indicates that there is no paper on considering the simultaneous formation of cells and layout under a dynamic condition.
Saidi-Mehrabad and Safaei [18] developed the dynamic CF model considering Cost of an inter-cell relocation for part type j based on the unit of distance number of variable cells for sequential planning periods and then solved the model by neural network in deterministic condition."