An approximation manpower planning model for after-sales field service support

Manpower planning is a key part of after-sales field service support with a service guarantee. Accurate field travel distance approximation presents a good opportunity to lower the manpower level. By explicitly considering the uncertainties, a state-dependent travel distance approximation model is presented and used to find the optimized manpower solution. A simulation model is developed to study the relationship between staffing level, travel distance, and percentage of customers serviced on time. Numerical results show that the proposed travel distance approximation model performs much better than the classical “square root law” and other models in the literature.