Agricultural mechanization
Mehdi Anafche; nasim monjezi
Abstract
Introduction: Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct ...
Read More
Introduction: Considering the high use of agricultural machines in sugarcane Agro-industry company; management of maintenance and repairs is necessary. The application of agricultural mechanization and the management of machines in agriculture is responsible for improving the way of working and correct use of machines. Today, with the mechanization of agricultural systems, the timely performance of activities requires correct machine planning. For proper planning, one must know the reliability of the machines. Increasing efficiency and reliability of machines is an economic necessity. Any scheduled program to increase the reliability of machines can be effective in reducing time loss due to repairs and cause repairs to be completed on time. Therefore, in this research, according to the nature of the project of annual repairs of MF 399 tractors, in which the activities and the time of their completion are possible, the graphic evaluation and review technique (GRET) method was used. GERT's method is one of the possible network programming methods. In GERT's method, the occurrence of activities is considered possible and a percentage of probability is assigned for the occurrence of each activity.Materials and Methods: This research was conducted in the Dehkhoda Sugarcane Agro-industry Company in the crop year of 2023-2024. Dehkhoda Sugarcane Agro-industry Company has 42 Messi Ferguson 399 double differential tractors. In this research, in order to schedule annual repairs, statistics and data related to the repairs of 22 MF 399 tractors were collected and the data of other machines were used to compare the actual repair time with the calculated schedule. The 13 repair items of MF 399 tractors used in the company include: engine, clutch, gearbox, differential and rear axle, brake, rear hub, body, front axle, hydraulics, electricity and battery, wheels, service and greasing. The work breakdown structure diagram and network model of annual MF 399 tractor repairs were drawn. To extract the time distribution density function of each activity, first the available information was collected for each activity, then the time distribution density function was determined for each activity. The time to perform the activities is fuzzy and they are expressed by triangular fuzzy numbers. In this research, after scheduling, the results obtained from GERT's method were compared with the actual time spent to perform annual MF 399 tractor repairs and the appropriateness of the estimates was determined. For this purpose, in order to determine the actual time of annual MF 399 tractor repairs, among the tractors available in the mechanical equipment department of Dehkhoda Sugarcane Agro-industry Company, in the crop year 2023-2024, a sample was randomly selected and the actual duration of repairs was determined. Then the actual time to complete the operation was compared with the expected time.Results and Discussion: The time to complete the annual repairs of MF 399 tractors was estimated to be 225.93 hours using the classic GERT method. But in GERT's Fuzzy method, the time calculated for annual MF 399 tractor repairs was (295.30, 232.07, 168.73) hours. The actual duration of annual repairs for 20 tractors (out of a total of 42 tractors) in Dehkhoda Sugarcane Agro-industry Company, which were repaired during the 2023-2024 crop year, according to the information available in the technical office of the company's mechanical equipment, was determined. 29.12% of the real times for completing MF 399 tractor repairs were estimated outside the fuzzy time. Therefore, the manager of the repair unit can reduce the cost of time loss and manage the time to complete the operation in the optimal time frame by using correct planning and reducing the reasons for the delay in the operation.Conclusion: Therefore, GERT F Fuzzy's method provides the possibility to the manager of the repair unit to set the completion time in the estimated range appropriately, taking into account other effective factors involved in the operation, so that there is no disruption in the implementation of activities and on the other hand, the costs to minimize when the work is not done. It also provides the possibility to create cuts at different times and control the operation process and modify it if needed. In the real world, due to existing uncertainties, there is not enough confidence in the duration of the annual maintenance of tractors, but nevertheless, the results obtained from GERT's method in this research are close to the actual time of completion of operations and make the estimates more appropriate.
N. Monjezi
Abstract
Introduction Currently, musculoskeletal disorders are one of the most common occupational diseases and one of the most common causes of absenteeism, which leads to a decrease in productivity. Postural assessment methods are considered pivotal in the investigation of the risks of developing job-related ...
Read More
Introduction Currently, musculoskeletal disorders are one of the most common occupational diseases and one of the most common causes of absenteeism, which leads to a decrease in productivity. Postural assessment methods are considered pivotal in the investigation of the risks of developing job-related musculoskeletal disorders. Various approaches are presented to assess the risk of injury in inappropriate postures. Agriculture is one of the most crucial sectors in both the developing and the developed countries since it ensures the food security of the country. In the process of producing sugarcane, a significant part of the stages of cutting, planting, and harvesting is done manually. A low level of knowledge about the correct condition of the body during work is one of the problems of farmers. Therefore, body status assessment methods are considered as the basis for assessing the risk of musculoskeletal disorders associated with work. Materials and Methods This research was carried out with the aim of analyzing the risk factors of occupational skeletal musculoskeletal injuries in sugar cane farmers using QEC method and Nordic questionnaire. The quick exposure checklist (QEC) quickly assesses the exposure to risks for work-related musculoskeletal disorders (WMSDs). QEC is based on the practitioners’ needs and research on major WMSD risk factors. The Nordic body map is given to the participants to be filled out with the assist of a student research assistant when needed. However, due to practical reasons, most participants are interviewed using the semi-structured method by a student research assistant. The Nordic body map consists of 28 parts of the body that must be rated based on the symptoms. Examples of the body parts are the right shoulder, upper arm, etc. The postures of 50 cutting workers, 200 planting workers, and 50 harvesting workers were selected by random sampling and analyzed using QEC2003 software. Results and Discussion According to the results of the Nordic questionnaire in manual cutting sugarcane, the most prevalent signs of musculoskeletal disorders were in the waist (80%), wrists and hands (78%), knees (74%), and feet (70%). In manual planting sugarcane, the most prevalent signs of musculoskeletal disorders were in the areas of the waist (89%), back (86.5%), and knee (84.5%), respectively. The findings also indicate that in the manual harvesting operations, the most prevalent signs of musculoskeletal disorders were the wrist and hand (88%), waist (84%), and foot (80%). The results of the Nordic questionnaire show that most disadvantages of cutting, planting, and harvesting in workers are visible in the lower back (80%), lower back (89%), and wrist/hand (88%), respectively. The prevalence of skeletal musculoskeletal disorders, especially in the waist, was observed among a high number of sugarcane producers. The results also showed that in the QEC method, in cutting, planting, and harvesting 44, 62, and 59 percent of workers’ postures were placed in the most critical group. In manual cutting of sugarcane, 30 percent of the workers were at the high-risk level and 44 percent of workers were at high risk, indicating the high risk of this operation, and that better preventive measures should begin as soon as possible. In the QEC method for manual planting of sugarcane, 7% of the postures of workers is acceptable and their risk is very low. Work posture for 9.5% of people requires more research and attention, and 21.5% of workers must be treated fairly fast. 62% of the postures of workers need to be corrected promptly. In the QEC method for manual harvesting of sugarcane, the posture requires 14% more research and attention, and 28% of workers should be treated fairly quickly. For 59% of postoperative workers, work should be promptly corrected. The QEC analysis showed that some of the work postures posed greater risks of MSDs to the workers with QEC scores. QEC helps to prevent many kinds of WMSDs from developing and educates users about WMSD risks in their workplaces. Conclusion The study has identified the body parts and tasks of the workers exposed to ergonomic risks through the Nordic questionnaire and the QEC method, respectively. Results from the study showed that the majority of the workers were having WMSDs.The physical condition of sugar cane production workers needs to be corrected. The ergonomic training course can have an impact on improving the working conditions of workers, but it is not enough, and it is a must-have for the sugar agro-industry to move towards all mechanized operations.