Abstract. Modern manufacturing firms should be supported by effective maintenance to become successful in their operations. One of the approaches for improving the performance of maintenance activities is to implement a total productive maintenance (TPM) strategy. Overall equipment effectiveness (OEE) is the key measure of TPM. According to the results of the literature review, the performance elements measured by the OEE tool are not sufficient to describe the effectiveness of TPM implementation. Hence, we aim at developing and evaluating new performance measures oriented towards the quantification of TPM implementation effectiveness under fuzzy environment. For the evaluation of each performance measure, at first, the nominal group technique has been used. Then to determine whether these performance measures are statistically significant, conjoint analysis based experimental design has been applied. In the second step, COmplex PRoportional ASsessment of alternatives with Grey relations (COPRAS-G) and the fuzzy COPRAS method has been developed to evaluate these performance measures in TPM. Proposed fuzzy COPRAS method gives the reassuring results of ranking newly developed performance measures in TPM.Keywords: COPRAS-G, performance measurement, new performance measures, total productive maintenance, conjoint analysis, fuzzy COPRAS.
IntroductionTPM is a new concept for maintenance that better optimizes the equipment effectiveness, minimizes breakdowns and encourages operators to autonomous maintenance for day-to-day activities involving total workforce (Andersson 2015). TPM aims to improve equipment effectiveness during the lifetime of the equipment.
664E. Turanoglu Bekar et al. Fuzzy COPRAS method for performance measurement in total productive ... Nakajima (1988) initiated TPM concept in the 1980s, which brought measurable metric named OEE for measuring productivity of individual equipment in a factory. It explains and measures losses of significant sides of manufacturing specifically availability, performance, and quality rate.OEE approach has been starting to be widely used as an important quantitative metric for measurement of productivity in manufacturing operations (Huang et al. 2003). The use of OEE varies from one industry to another, and it is tailored to fit to comply with industries' specific requirements.According to the literature review on performance evaluation in TPM, OEE metric has widely been used as an important performance measure, but it is not adequate to define the effectiveness of TPM. Jeon et al. (2011) also suggested measuring the performance of TPM in terms of efficiency. This has caused to a requirement for a thoroughly described performance measurement system for TPM which is capable of considering different significant elements of productivity in a manufacturing process. Therefore, in this study new performance measures having an impact on TPM are proposed and proposed performance measures are evaluated under fuzzy environment.The innovative side of this study is to develop new per...