Machine replacement scenario analysis: a case study of food industry

Abstract

Machine replacement is one of the major problems for a maintenance department. One of the trends in food consumption is the use of ready-to-eat meals. In Asian countries most meals are an integration of a major part of rice with minor parts of vegetables and/or meat. With ready-to-eat manufacturers, the rice cooker is an important machine to produce rice as a main ingredient. Our objectives are to estimate the lifetime of parts of an automatic rice cooker and to determine when to replace the parts by scenario analysis. We study the worst cast, best case, average case and simulation for two situations: before and after Total Productive Maintenance (TPM) implementation. The input parameters include the lifetime and cost of 30 parts of a rice cooker. For the purpose of a simulation analysis, the lifetimes of the parts are considered to be random variables according to a probability distribution determined by a simulation software. The output of the simulation is the total maintenance cost of the parts replacement between one and ten years. In other cases, the lifetimes of parts are determined based on a scenario such as minimum, maximum and expected value of lifetimes according to the historical data and supplier data. The result shows that the average case model after TPM implementation is the best estimator with 10.55% difference to the actual maintenance cost. The simulation after TPM implementation is the second best method with 16.97% difference. It implies that the TPM implementation is able to lengthen the part life and results in maintenance cost reduction. In addition, the inventory of parts is categorized by means of ABC classification. It helps to allocate the resources to monitor the right parts. In summary, the average case analysis should be implemented to determine when to replace a part and to estimate the maintenance cost of rice cooker. In the future, this model might be used as a decision support system for investment of different types of machines.