DEVELOPMENT OF MAINTENANCE PLANNING MODEL FOR A CREW SIZE UNDER VARYING SKILLS AND JOB COMPLEXITY

Abstract

Many studies have been carried out on maintenance models with regards to long term manpower planning. However, determining the size of maintenance workforce is an essential element of maintenance planning. It is important for performing maintenance programs perfectly. Although, it is a complex and challenging problem since it involves the consideration of several important factors. The model developed in this research aims at finding out the optimal size of the maintenance workforce taking into account all of the important factors that affect this size. It is based on determining the needed number of workers with different skill levels and different costs to meet maintenance workload of different grades that is to be performed in a specified planning horizon with minimum cost. A production workshop in Bida was used as case study where data were collected for appropriate call in jobs with service personnel clustered into engineers, Technicians and craftsmen. The results had varying skills measured in years and cost as the major considerations for evaluating their performance and a software package was developed for quick implementation of this research using visual basic language 6.0. The complications inherent in the problem environment to include a non random arrival pattern of jobs were incorporated into the software developed. The results showed that the varying crew sizes with different years (skills; 1-2years, 3-4years, 5-6years, 7-8years, 9-10 years ) deployed to six equipment units had an optimum cost region obtained through a graph of the maintenance service time cost. With optimum cost of ₦1900 daily within 3-6 years for the multi skilled crews