ASSIST is a structured parallel programming environment targeting networks/clusters of workstations and grids. It introduced the parmod parallel construct, supporting a variety of parallelism exploitation patterns, including classical ones. The original implementation of parmod relies on static assignment of parallel activities to the processing elements at hand. In this work we discuss an alternative implementation of the parmod construct that implements completely dynamic assignment of parallel activities to the processing elements. We show that the new implementation introduces very limited overhead in case of regular computations, whereas it performs much better than the original one in case of irregular applications. The whole implementation of parmod is available as a C++/MPI library.