Paper Title
Utilization of New Definitions to Calculate Overall Equipment Effectiveness for Air Compressors: A Case Study

Abstract
There are growing needs for energy in the 21st century, while as a part of sustainable development and environmental considerations, using energy resources wisely and responsibly is a great importance. In this regard, companies are moving towards new methods to put their machines to optimal working condition. Compressed air has been used in the industries for several years and it is one of the most expensive energy resources which is mainly produced by compressors, turning electricity to potential energy stored in compressed air. As this equipment showed its vital role in the different industries such as car manufacturing, it is necessary for managers to know how effective their equipment are working. Iran Khodro Company; the biggest car manufacturer in Iran and also in the Middle East, is not an exception. In many parts of this company like body shops, paint shops and press shops, compressed air that is produced by different types of air compressors is being used. Because of this, managers and other authorities need to know about their equipment effectiveness. In order to do that, engineers in this section faced some difficulties to find a way to calculate this factor. To demonstrate the technique, time interval has been limited between march to august of 2017 in terms of the number, timing and impact of downtime and efficiency of each Compressor Brigade for Iran Khodro Company will be performed in terms of the amount of compressed air produced in proportion to the energy consumption of a specific compressor using the calculation of the relevant indices. Effect of the efficiency of each compressor for the compressed air department of Iran Khodro in terms of the amount of compressed air and its energy consumption, as well as analysis based on the failure rates and their repairs and overhauls costs based on the calculation of relevant indicators such as PM Rate, Range Rate, Mean Time To Repair (MTTR), Mean Time Between Failures (MTBF), Mean Time To Failure (MTTF), Availability (AV), and finally the OEE (Overall Equipment Effectiveness) which is a Management Indicator. In this paper, the analysis of the compressors used in Tehran site of Iran Khodro Company in terms of efficiency and calculation of maintenance indicators, as well as management indicators such as OEE index have been introduced, as well as defining the term "Quality" in OEE calculation. Keywords - Compressors Maintenance, Effective Planning, Equipment Health Assessment, Overall Equipment Effectiveness (OEE).