In the paper, the problem of efficient parallel execution of numerical algorithms for supercomputers in the LuNA system is concerned. With LuNA, an application algorithm is represented in a hardware-independent high-level form. This allows implementing the algorithm by automatic construction of various parallel programs, which possess different non-functional properties, such as execution time, memory consumption, network workload. In the LuNA system, the efficiency problem of automatically constructed parallel programs is dealt with through the behavior concept. The presented approach allows controlling parallel program behavior without low-level programming of the desired behavior.