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Once a unit experiences a service downtime or downgrade; the covariates or risk factors can directly shows impact on the delay in repairing activities. In this paper, the risk factors are revealed that either delay or accelerate repair times, and it also demonstrates the extent of such delay, attributable to the underlying characteristics of the equipment. The potential risk factors provide necessary inputs in order to improve operation performance. Once risk factors are detected, the maintenance planners and maintenance supervisors are aware of the starting and finishing points for each repairing job due to their prior knowledge about the potential barriers and facilitators. This study employs semi-parametric approaches in a different way to examine the relationship between repair time and various risk factors of interest. The properties of the hazard function for the repair time problem are critically examined and the major findings are highlighted. This paper focused to estimate underlying characteristics of the machines during failures, which may prolong the troubleshooting time. An empirical study has been accomplished to estimate the risk factors. There are 1203 ir conditioners maintenance records in 2011 and 2012 are collected from food industries in Malaysia. The empirical studies estimates repair time data and background characteristics of the machines.

The current trend towards industrial robotics requires the development of simple programming techniques. Programming by demonstration has emerged as one of the most promising solutions for effective programming of robot tasks (Ikeuchi & Suehiro, 1994; Zollner et al., 2002). Contour following is one of basic task in industrial robot manipulation. In this task, the robot is holding a tool to follow the contour of an object whose shape and pose are often unknown (Mi & Jia, 2004). These applications include part polishing, inspection, sealing, painting, cleaning, modeling, etc. During the following process, the tool is constrained on the surface to maintain contact force while moving along some tangential direction. In order to use robotics for such application two sequences of step need to be considered, the programming phase and the playback phase. In the programming phase, teaching a group of points is required while for playback phase, the robot Tool Centre Point (TCP) will follow the taught points recorded previously. This programming phase especially for contour following application is quite tedious and time consuming. For example, in order to track an arc, the robot programmer needs to manually use teaching box or teaching pendant to jog (powered motion) the robot Tool Centre Point to three points that enclosed an arc. For a complex contour, several series of three points must be taught, besides finding the optimum process parameter (voltage, current and electrode speed for arc welding application) related to those points. Next, the motion instruction, speed and type of termination that describes the closeness of zoning radial distance to the taught points needs also to be defined. The programmer must iterate the points and process parameters several times until the optimum combination are achieved. In comparison to assembly operation where the programmer just need to teach few points such as approach, insert and depart points, contour following for painting, arc welding and sealing application requires a large number of points recorded and at the best location. After all the best program and process 17

The research is based on the fact that decision support systems (DSSs) is needed for maintenance process in commonly industries. Many maintenance functions with varieties optimization models and techniques have been proposed for solving the problems. The aim of this research was to identify those optimization models and techniques to conduct maintenance decision support system in small and medium industries (SMIs). A systematic literature review was performed to gather relevant information. The results shown several trends related in the fields area. Next, the research direction has been suggested to develop the systems.