Many scheduling algorithms have been devised for nested loops with and without dependencies on gen- eral heterogeneous distributed systems ([1] and refer- ences therein). However, none addressed the case of dynamically computing and allocating chunks of non- independent tasks to processors. We propose a theo- retical model that results in a function that estimates the parallel time of tasks in loops with dependencies on heterogeneous systems. We show that the mini- mum parallel time is obtained with a synchronization frequency that minimizes the function giving the par- allel time. The accuracy of the model is validated through experiments from a practical application. For more details refer to [2].