Main Article Content
Abstract
PT. XYZ is a manufacture company which is running production home appliances, such as refrigerator dan freezer. At the moment, problem faced by company is damage at existing machines which causing high production loss. As the results are production demands are not being met and job tardiness incurs. Through data which have been collected, can be known that PU-80 cabinet injection machine owning the biggest downtime than others. Downtime of PU-80 cabinet injection machine most commonly caused by three critical component namely chemical filter, multivalve, and head component PT. XYZ has planned and executed production scheduling and preventive maintenance planning independently in spite of the inter-dependent relationship between them. This research suggests the integrated production scheduling and preventive maintenance planning model for PU-80 cabinet injection machine to solve these two problems simultaneously. Failure rate distributions of the production lines are known based on data and preventive maintenance is necessary to keep the yield of the system at the required level. The method which will be implemented is genetic algorithm. The focus of this paper is optimizing integrated production and preventive maintenance scheduling by minimizing total tardiness cost. The results of this research is the optimal time to execute replacement critical components for PU-80 cabinet injection machine in the next 6 months from October 2008 until March 2009. From the calculation, it concludes that the optimum interval time to replace chemical filter component is every week ,for multivalve component the replacement is done in third week of Desember 2008, and replacement for head component is done in first week of March 2009.
Keywords: preventive maintenance, production scheduling, tardiness cost, and Genetic
Algorithm.