Mixed integer linear programming model for workload leveling on offshore platform of Petroleum Company

Abstract

The problem of automatic workload leveling and optimizing occurring in the maintenance and inspection section on offshore platform of a major petroleum company in Thailand is studied. Efficient equipment and offshore personnel are the most significant factors in providing more efficient products and services. Therefore, each year the department receives a tremendous number of maintenance and inspection work orders regarding a large number of equipments on offshore platforms. Workload leveling is needed in order to distribute all works for limited number of personnel and accommodations on offshore platform. Mixed integer linear programming (MILP) technique using branch and cut method is utilized for this problem. The model aims to balance and minimize the number of personnel working offshore while maintaining all work requirements. Researchers use the open source optimization software GUSEK to determine the optimal resource allocation. We determine the nearly optimal solution by reducing the number of iterations using the mipgap which is considerably faster than the original MILP. The results indicate that less number of personnel are employed and personnel are more leveling when compared with the original data from yearly work order plan of the company.