Ali Rastegari

Maintenance decision making, supported by computerized maintenance management system

This paper is written based on the need for Computerized Maintenance Management Systems (CMMS) decision analysis capability to achieve world class status in maintenance management. Investigations indicate that decision analysis capability is often missing in existing CMMSs and collected data in the systems are not completely utilized. How to utilize the gathered data to provide guidelines for maintenance engineers and managers to make proper maintenance decisions has always been a crucial question. In order to provide decision support capability, the aim of this paper is to provide and examine three different decision making techniques which can be linked to CMMS and add value to collected data. This research has been conducted within a global project in a large manufacturing site in Sweden to provide a new maintenance management system for the company. The data from the main studies were collected through document analysis complemented by discussions with maintenance engineers and managers at the case company to verify the data. Methods including a Multiple Criteria Decision Making (MCDM) technique called TOPSIS, k-means clustering technique, and one decision making model borrowed from the literature were used. The results indicate the most appropriate maintenance decision for each of the selected machines/parts according to factors such as frequency of breakdowns, downtime, and cost of repairing. The paper concludes with a comparison of results obtained from the different decision making techniques and also a discussion on possible improvements needed to increase the capability of the maintenance decision making models.

Cost effectiveness of condition based maintenance in manufacturing

This paper presents a proposed guide for analysis of the costs and benefits of implementing Condition Based Maintenance (CBM) in manufacturing industry. The guide will be exemplified with results from a case study performed in a real CBM implementation in hardening and machining processes in a large manufacturing facility. The result indicates factors that ought to be taken into consideration in order to evaluate both the cost of implementing CBM and its benefits. These factors indicate the benefits of CBM mostly by reducing the losses due to damage in the production equipment, including capital loss, production loss, quality loss, environmental loss, safety loss etc. By analyzing the empirical data, the most potential savings by implementing CBM are presented as; reducing the probability of having maximal damage in the production equipment and, reducing production losses particularly in high production volumes.

Implementation of Condition Based Maintenance in manufacturing industry - A pilot case study

This paper presents a guide for implementation of Condition Based Maintenance (CBM) in a manufacturing industry, considering the technical constituents and organizational aspects when implementing CBM. The empirical base for the study is a case study from a major manufacturing site in Sweden. The data was collected during a pilot project to implement CBM at the case company. The purpose of the pilot study at the company was to implement online condition monitoring on some of the critical components in the hardening process. Hereby, two of the main online condition monitoring techniques namely vibration analysis and Shock Pulse Method (SPM) have been implemented and tested on electric motors to monitor bearing conditions. The paper presents the process of implementation and the elements included in this process. Some of the main elements in the implementation process are selection of the components to be monitored, techniques and technologies as well as installation of the technologies and finally how to analyze the results from the condition monitoring. The data from online condition monitoring on the electric motors, driving the furnace fans, are recorded and presented in the paper including breakdown data on two objects. This information is leading to useful and reliable knowledge for maintenance work to be cost effective and be able to increase the overall equipment availability (OEA). In addition to this, the result indicates to what extent advanced CBM practices are applicable in the hardening environment in the manufacturing company and it provides guidance for further research and development in this area. The paper concludes with a discussion on possible future trends and research areas, needed to increase the effective and efficient use of CBM.