كاربرد روش گرت فازي در زمان بندي عمليات توليد نيشكر

Application of fuzzy GERT method in operations scheduling of sugarcane production

در برنامه ريزي عمليات مكانيزه كشاورزي، عدم توجه به زمان بهينه انجام عمليات، باعث كاهش چشم گيري در ميزان عملكرد محصول مي شود. در اين تحقيق به علت توانايي و قابليت شبكه گرت، از آن به عنوان ابزاري توانمند در برنامه ريزي و زمان بندي عمليات توليد نيشكر در استان خوزستان استفاده شد. اطلاعات مورد نياز از طريق منابع مختلفي مانند گزارش ها، آمار و اطلاعات ايستگاه هاي هواشناسي مستقر در شركت هاي كشت و صنعت نيشكر، نظرات كارشناسان و محققان موسسه تحقيقات و آموزش توسعه نيشكر، استفاده از گزارش ها و آمار ساليانه عمليات هر واحد توليدي در كشت و صنعت ها ي نيشكر و نظرات كارشناسان و متخصصان واحد هاي توليدي در كشت و صنعت ها گردآوري شد. با جمع آوري اطلاعات لازم، فعاليت ها تعيين و شبكه گرت ترسيم شده و مورد تجزيه و تحليل قرار گرفت. زمان اتمام عمليات با استفاده از روش گرت فازي برابر (472/42، 368/72،272/51) روز به دست آمد. نتايج نشان داد كه مدل شبكه حا صل، توانايي پاسخ گويي به سئوالات آماري در مورد عمليات توليد نيشكر را دارد و همچنين مد شبكه حاصل ديد روشني براي مدير واحدزراعي جهت اتخاذ تصميمات به موقع فراهم مي آورد تا در مرحله اجرا و عمل، طبق برنامه ريزي پيش رفته و بتواند عمليات را در زمان مطلوب و با هزينه مناسب به اتمام برساند.

Introduction In agricultural mechanization projects, operations or activities of the project must be accomplished on time with well-defined sequence and short time span, if timelines costs are to be avoided. GERT Networks have most of the advantages associated with networks and enable the system analyst in exact evaluation of certain types of networks. Graphical Evaluation and Review Technique (GERT) is a systems analysis technique for project management. GERT provides a visual picture of the system and helps to analyze the system in a less inductive manner. Therefore, the purpose of this paper is studying the application of project scheduling in agriculture, for operations scheduling of sugarcane production using the fuzzy GERT method in Khuzestan province of Iran. Materials and Methods The study was carried out in Khuzestan province of Iran in 2015. In this research, GERT Networks were used and operations scheduling of sugarcane production in Khuzestan province of Iran was analyzed as a case study. Data were collected from a variety of sources such as reports and statistics of meteorological synoptic stations, opinions and comments of Khuzestan Sugarcane and by-Product Research and Training Institute experts and reports and statistics of Sugarcane Agro-Industry. All activity times are given in day. At first, the project activities are determined. Because the activity durations in project networks are usually difficult to estimate or determine exactly, it is reasonable to represent them as linguistic variables or fuzzy numbers. In this paper, the operation time for each activity is characterized as a positive triangular fuzzy number. Finally, GERT network was plotted and analyzed. Results and Discussion Correct scheduling of agricultural mechanization project is the necessary condition for the project success therefore GERT network of sugarcane production was plotted. The advantage of GERT network in the present context is two-fold. Firstly, this procedure gives the visual picture of the inspection system and secondly, it enables a thorough characterization of sugarcane production. In this project, after defining the activities, we estimate the fuzzy triangular number for each activity as a time. Then we solved the network with fuzzy GERT method. The GERT network model resulted from sugarcane production as follows (Fig. 3). Parameters of sugarcane production GERT network are presented in Tables 1 and 2. The Project fuzzy completion time with the method of fuzzy GERT is equal to (161.7, 212.2, 268.2) days. The Completion time of part II is . As a result, The fuzzy time completion of operation of sugarcane production is equal to (272.51, 368.72, 472.42) days. Results showed that the network model was able to answer any statistical questions concerning the project and the network model is an increasingly powerful tool to help a project manager to make an optimal decision. It serves as the basis for monitoring and controlling project activities and, taken together with the plan and budget, is probably the major tool for the management of projects. And the project finished in proper time and cost. Conclusions The Fuzzy GERT network due GERT capabilities (using logical nodes and branches and loops) in modeling of research projects and fuzzy ability for uncertainty of project parameters (time, activity definition and sequence) is suitable especially for agricultural mechanization projects scheduling. The Fuzzy GERT network is the same probability GERT network that fuzzy parameters have replaced probability parameters and are composed of 3 parts: logical nodes, fuzzy branches and loops. For the first time in this method, a GERT network computation is performed based on nodes and resembling fuzzy CPM method (forwarding computation). In this method, nodes were evaluated from the start node to the end node. Nodes evaluating was done based on input and output activities to every node. Process outputs are scheduled network and project fuzzy completion time. Results of this model include the following items. The model necessitates the preplanning. It increases the harmony and coordination. It usually predicts and determines the troublesome items. It specifies and segregates the responsibilities. It refines the thoughts and increases the knowledge of the user about related subjects and their relative importance in the whole operation. It attracts the management attention to those activities which may face problems or seem to be associated with them. It specifies the optimum start and finish points of each activity in the operation. It facilitates the possibility of readjusting of the project for new conditions. It facilitates the reporting and instructing procedures. It is a very useful device for educating employees in different fields of operation. It is the most suitable tool for presenting the organizational chart and their relation. It shows the relation between activities. It is adjustable and also updatable. Changing and modifying the program in new and unprecedented situations will be accomplished easily. Every parts of the network can be changed easily. This research is the first report performed in the agricultural mechanization of the world.