Bus fleet data have consistently shown that vehicle operating and maintenance costs increase as vehicles age. A fleet manager has to deal with the tradeoff between the lower operating and maintenance costs of newer fleets and their higher initial capital costs as well as the tradeoff between conventional and fuel efficient bus technologies. This study formulates and implements a fleet replaceme...

This paper considers replacement polices for an extended cumulative damage model with minimal maintenance at each shock and minimal repair at failure: A system is replaced at time T or at shock number N , and undergoes maintenance or repair between replacements. The expected cost rate is obtained and each optimal T ∗ and N∗ to minimize the cost rate is discussed. It is shown that this model wou...

This paper presents a special case of integration of the preventive maintenance into the repair/replacement policy of a failure-prone system. The machine of the considered system exhibits increasing failure intensity and increasing repair times. To reduce the failure rate and subsequent repair times following a failure, there is an incentive to perform preventive maintenance on the machine befo...

preventive maintenance scheduling of generating units is addressed as a long-term scheduling in power system studies aiming to increase the reliability incorporating cost reduction. it consists of knowing which generating units should be shut down for regular safety inspection. in this paper, a new formulation of preventive maintenance scheduling associated with cost reduction index (cri) is pr...

In every field of our real life situations, we deal with a replacement problem, when some items such as machines, medical equipment, military tank, electric bulb etc. or workers need to replace due to their decreased efficiency, failure or break down. To get a more realistic view of a replacement problem, here, we consider that the capital cost ( C ~ ), scrap value or resale value ( S ~ ), main...

There are fewer problems encountered with optical voltage transducers in comparison with their inductive and capacitive counterparts. Although capacitive and inductive transformers are used vastly for the purpose of measurement and protection in the networks, they cause problems such as core saturation and improper transient responses which decrease the accuracy of measurement and eficiency of ...

This study aims to select optimal maintenance strategy for components of an electric motor of the National Iranian Oil Refining and Distribution Company. In this regard, a method based on revised multi choice goal programming and analytic hierarchy process (AHP) is presented. Since improving the equipment reliability is an important issue, reliability centered maintenance (RCM) strategies are i...

Evaluation of the reliability parameters in micro-grids based on renewable energy sources is one of the main problems that are investigated in this paper. Renewable energy sources such as solar and wind energy, battery as an energy storage system and fuel cell as a backup system are used to provide power to the electrical loads of the micro-grid. Loads in the micro-grid consist of interruptible...