Rowland Jerry Okechukwu Ekeocha

Dynamic Modeling of Machinery Replacement Problems: Machinery Replacement Model Rowland Jerry Okechukwu Ekeocha

The effect of deterioration on resale value is examined in this study. Previous works on machinery replacement placed emphasis on the maximization of total maintenance costs and the minimization of profit without recourse to the effect of deterioration on the resale value. Some models exclude resale value in cost build-up. In other models values of deterioration are assumed or at best determined by highly subjective and expensive methods. In this work, deterioration values are generated as random numbers using the Monte Carlo simulation under the uniform probability distribution. The dynamic programming enumeration process is adopted as the solution technique. The model is calibrated and the results are verified with field data from different industries. Finally,the results of the model are compared with those of existing models. Basically,the results show that the model is reliable,operational and simple in application. The results show that the measured and predicted total costs are positively correlated with correlation coefficients between 0.72 and 0.99 for the machines considered in this work. The results show that the replacement dates are between 4&6years for construction machines.