Application of Non Linear Programming to Locomotive Optimisation: A Case Study of National Railway of Zimbabwe

This paper analysed activities undertaken in optimizing locomotive utilisation at National Railways of Zimbabwe (NRZ). Failure to attain breakeven and meet set targets is associated with underutilising resource capacity. The identified locomotive constraints in this paper do not have a linear relationship hence the application of nonlinear programming in formulating the Locomotive Optimization Model (LOM). The objective function in the model is to maximize the quantity of traffic moved by a given number of locomotives available for use which consequently converts to revenue generated. The model results show a failure by NRZ to meet breakeven targets in the year 2013. Different model scenarios are formulated using attainable locomotive figures and it is observed in the model scenario B where a 15% increase in speed, trailing load and availability of locomotives will results in attainment of breakeven targets.