Equipment Renewal Scheme Based on the Optimal Comprehensive Method

The least total cost method has been proposed by the existing literature to identify the optimal scheme of equipment renewal when the lifetime of project is limited. But this method does not take account into the condition that the renewed equipment will need to be renewed again when its service time exceeds its economic life limit. Hence, the scheme, chosen by this method is not absolutely the optimal scheme. It has not considered the comprehensive scheme of utilizing the old equipment for some time before renewing with the new equipment. Compared with the new equipment, the old equipment has the cost advantage in a short period of time, and it´s economic to utilize the old equipment for a little longer. Besides the least total cost method, we use the re-renewal method and the optimal comprehensive method to determine the best scheme, then the three methods are compared to illustrate the advantage of the optimal comprehensive method. It indicates that the equipment renewal scheme based on the comprehensive method can reduce the overall costs of the project much more and have rather good values in practical application.