The multiprocessor scheduling problem is to allocate the tasks of a parallel program to processors in a way that minimizes its completion time. Task scheduling on multiprocessor is NP-complete. This paper solves the task scheduling on heterogeneous computing systems using segmented MaxRMinCT heuristic with robust metric. A schedule is said to be robust if it is able to absorb some degree of uncertainty in tasks execution time while maintaining the stable solution. Robustness can be defined as the degree to which a system can function correctly in the presence of parameter values different from those assumed.