12/17/2023 0 Comments Masej ferguson traktorMonte-Carlo simulation then calculates results over and over, each time using a different set of random values from the probability functions. Each individual is chosen randomly and entirely by chance while each individual has the same probability of being chosen at any stage during the sampling process, and each subset of k individuals has the same probability of being chosen for the sample as any other subset of k individuals. A simple random sample is a subset of individuals (a sample) chosen from a larger set (a population). 13 Monte-Carlo simulation relies on repeated random sampling to obtain numerical results. In other words, Monte-Carlo simulation produces distributions of possible outcome values based on an idea of using randomness to solve problems that might be deterministic in principle Salami. Testing the model showed that the costs were more realistic when the area worked was considered instead of the operating hours.Īfter estimation of functions by using available life and repair data, a widely applied method namely Monte-Carlo simulation method was employed to simulate tractors life and repair characteristics for longer time. Rotz 12 developed a model based on equipment price and operating hours. 10 Liange 11 used Exponential function for estimation of farm machinery failures. 9 Another study showed that the failures of combine harvester John Deer 955 followed 2-parameter Weibull function Vafaee et al. In a study it has been found that the reliability function of failures data of tractors Massey Ferguson 285 can be estimated by an Exponential function Poozesh et al. 7 Weibull functions with wider applications can be descending, ascending or constant based on the function parameters Bartkute et al. The common life distribution functions for continuous data are Normal, Exponential, Logarithmic and Weibull Haj Shirmohammadi. 6 In addition, the required number of repair-mans can be predicted by simulation of data in such a way that farm machines imposes minimum waiting time for repair. 3 Having an effective repair and maintenance program, the costs of machinery maintenance and failures will be reduced to an optimum point Lips et al., 4 by gathering machinery failures data on the farms, the failures distribution function can be estimated well and then some important issues such as machinery reliability and energy failures can be predicted as well Barabadi et al., 5 Billinton et al. 2 The cost of farm machinery repair and maintenance can contribute to most of farm machinery operational costs (after fuel) which can be reached to 15-60% of total crop production costs Mobley. owning or fixed costs and operating or variable costs Morris. Farm machinery costs are divided into two categories, i.e. 1 However, farm tractors stop due to break downs and it is desired that they repaired on a minimum time and back to farms. Farm managers are usually looking for high reliable farm machineries to complete necessary operation in the pre-determined time Hunt. Thus, any failure in farm tractors influences the series of field operations. It is even used for harvesting crops in some areas. Farm tractors are important machines that used for soil tillage, crop planting and protection. In order obtain suitable and effective farm machinery performance besides higher crop yield, on time farm machinery field operations are essential. Keywords: life distribution function, farm management, maintenance engineering Introduction Furthermore, two repairmen should be employed to have minimum waiting time to repair and maximum economic benefits from the view point of useful tractors working hours. Exponential for life and 2-parameter Weibull for repair. The results showed two functions for life and repair times i.e. Then, the Monte-Carlo simulation method was applied to simulate tractors working conditions for around 3500hours to have more reliable estimation of life and repair distribution functions. The tractors working data were gathered for 1100hours. two Massey Ferguson 285 and one Massey Ferguson 399. In the current study, the life and repair distribution functions of three tractors were estimated, and then, the necessary number of repairmen was determined in such a way that supplies the minimum waiting time to repair in one hand, and maximum human productivity is obtained in the other hand. Also, using human resources productively and its productive enhancement needs appropriate planning. In order to reach suitable and effective performance of farm machines, on time agricultural operations is important.
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