in the process of milk production, the highest cost relates to animal feed. based on reports provided by the experts, around seventy percent of dairy livestock costs included feed costs. in order to minimize the total price of livestock feed, according to the limits of feed sources in each region or season, and also the transportation and maintenance costs and ultimately milk price reduction, o...

maintenance process is one of the most necessary processes in every organization, whose main task is maintaining machines in desired conditions or restoring machines from non-optimal (nonoperational)conditions to optimal (operational) conditions. machines failure would result in loss of machines availability time, and rise of both organization costs and production time. also, it may cause irrep...

Reverse supply chain is a process dealing with the backward flows of used/damaged products or materials. Reverse supply chain includes activities such as collection, inspection, reprocess, disposal and redistribution. A well-organized reverse supply chain can provide important advantages such as economic and environmental ones. In this study, we propose a general framework and formulate a m...

U.S. Class I railways maintain their infrastructure through a mix of ordinary maintenance and periodic renewal of infrastructure components. Different railways use different proportions of ordinary maintenance and periodic renewal with little consensus as to the best combination. Furthermore, the cost-effectiveness of emphasizing one method over the other has not been analyzed using empirical d...

This paper deals with the problem of integrating noncyclical preventive maintenance and tactical production planning for a single machine. We are given a set of products that must be produced in lots during a specified finite planning horizon. The maintenance policy suggests possible preventive replacements at the beginning of each production planning period, and minimal repair at machine failu...

During the operation, the distribution transformer performance will deteriorate. The maintenance is an essential task in enhancing the safety of distribution transformer. Based on equal deterioration theory, the relationship among distribution transformer failure rate in each period of maintenance was deduced. After analyzing the maintenance costs and the failure costs in detail, the model of o...

Exergy analysis is based on combined first and second laws of thermodynamics and is a useful tool to analyze the energy systems in a better and more realistic way than an energy analysis, based on the first law of thermodynamics. Combination of exergy from thermodynamics with conventional concepts from engineering economy which is referred to as thermo-economy (exergo-economy) is a valuable too...