Development of efficient numerical programs for large distributed parallel computers is a challenging problem. Many programming languages, systems and libraries exist and evolve to help with it, yet the problem is far from being solved. Of interest are particular application implementations’ studies, which reveal actual capabilities of a system in the real computation. In this paper, the implementation of an indicative 3D model heat equation parallel solver using fragmented programming technology and LuNA system is investigated. A comparative testing with conventional MPI implementation is presented. The pros and cons of the approach are analyzed for corresponding applications class.