اندازه گیری عملکرد تعمیر و نگهداری - در جستجو برای یک شاخص بهره وری تعمیر و نگهداری

A partial maintenance productivity goal is that the firm should seek to maximize its maintenance productivity in economic terms, and should aim at producing any level of output which is decided upon at minimum maintenance cost with respect to the production system's state. The state of objects or production systems is such a property, i.e., a multidimensional property. In this paper we amalgamate these various dimensions into a single measure of the property involved. All things considered it would seem, that in measuring partial maintenance productivity, minimization of maintenance costs is incorporated as a subgoal, based on the maintenance inputs called for an “optimal budget”. These imputed maintenance costs do not have to be calculated separately, but emerge as a by-product of finding a high productivity index. In our partial productivity model, the output prices of the produced products and input prices (maintenance costs) will change over time. Expected changes in the prices of outputs and of current inputs would be built into the model.

The purpose of maintenance management is to reduce the adverse effects of breakdown and to maximize the production system availability at minimum cost. Production system breakdown causes a loss of output. Traditionally, there are two primary approaches to achieve such a purpose. The objective of preventive maintenance is to reduce the probability of failure in the time period after maintenance has been applied. Another is corrective maintenance, which strives to reduce the severity of equipment failures once they occur. Between these two maintenance tactics, preventive maintenance generally has attracted more attention in industry and academic research 1, 2, 3, 4 and 5. Previous research has shown that the use of preventive maintenance procedures may contribute to a rational way of maintaining and operating equipment. Characteristics of the two functions production and maintenance is presented in a simple chart in Table 1 [6]. In addition to these characteristics, both functions must similarly prioritize their activities and provide the right material at the right time. In another study, involving 340 plant engineering and maintenance supervisors, approximately 42% responded that scheduling maintenance activities is one of their three biggest problems [7]. Table 1. A comparison of production and maintenance characteristics [6] Production Maintenance (1) Many components (1) Many components (2) Many inputs (2) Many inputs Labour Labour Equipment Equipment Overhead Overhead Materials Materials (3) Discrete outputs which can be inventoried (3) Diverse outputs which are consumed opon creation Table options Historically, the relationship between maintenance and production has been characterized by conflict [8]. Typically, production departments do not readily release equipment for scheduled maintenance. Hence, the firms maintenance policy may in certain cases consist of only emergency maintenance. Although a firm may utilize a maintenance policy incorporating scheduled maintenance activities, emergency maintenance cannot be entirely eliminated. In order to determine the levels of maintenance a multitude of information is required. The costs of maintenance, estimated to be between 15% and 40% of production costs [9], and the trend toward automation has forced managers to pay more attention to maintenance. Managers have figured out, that maintenance, with its high cost and low efficiency, is one of the last cost saving frontiers in management [4]. This paper provides a conceptual framework as well as some results regarding maintenance policies and development of a maintenance productivity index.