farm machinery managers often need to make complex economic decisions on machinery replacement. repair and maintenance costs can have significant impacts on this economic decision. the farm manager must be able to predict farm machinery repair and maintenance costs. this study aimed to identify a regression model that can adequately represent the repair and maintenance costs in terms of machine...

The cell formation (CF) is one of the most important steps in the design of a cellular manufacturing system (CMS), which it includes machines’ grouping in cells and part grouping as separate families, so that the costs are minimized. The various aspects of the problem should be considered in a CF. The machine reliability and the tool assigned to them are the most important problems which have t...

nowadays, scheduling problems have a considerable application in production and service systems. in this paper, we consider the scheduling of n jobs on a single machine assuming no machine idleness, non-preemptive jobs and equal process times. in many of previous researches, because of the delivery dalays and holding costs, earliness and tardiness penalties emerge in the form of linear combinat...

to reduce the storing space and handling costs for hay/straw bales, recompressing the original bales after adequate hay drying is recommended. in this project, a recompression machine was designed, constructed and evaluated. solidwork and nastran software were employed to model, and to analyze the stresses in the components of the machine, respectively. the components of the machine consisted o...

This paper employs an interactive possibility linear programming approach to solve a single machine scheduling problem with imprecise processing times, due dates, as well as earliness and tardiness penalties of jobs. The proposed approach is based on a strategy of minimizing the most possible value of the imprecise total costs, maximizing the possibility of obtaining a lower total costs, and mi...

This paper deals with the determination of machine numbers and production schedules in manufacturing environments. In this line, a two-stage fuzzy stochastic programming model is discussed with fuzzy processing times where both deterioration and learning effects are evaluated simultaneously. The first stage focuses on the type and number of machines in order to minimize the total costs associat...

The purpose of this study was to evaluate the profitability of hatchery litter recycling into poultry feedstuff supplement. The data were collected in 2011 in 4 provinces, by direct interviewing of all hatcheries which used the hatchery litter drying machine. Net Present Value (NPV), Benefit-Cost Ratio (BCR), and Internal Rate of Return (IRR) methods were applied for this analysis. In the studi...