PURPOSE: To facilitate external insertion at the time of large scale parallelism and to effectively support tuning work by providing a parallel execution performance information acquiring means, speed acceleration rate calculating means and execution performance predicting means.

CONSTITUTION: A problem area defined as the target of parallel calculation is divided into plural partial areas and allocated to respective processors. A calculating means 1 executes the parallel calculation to plural cases corresponding to the number of divided meshes in the problem area and outputs execution performance information such as calculation time. This information is acquired by an execution performance information acquiring means 2. Concerning each case from this execution performance information, a speed acceleration rate calculating means 3 calculates a speed acceleration rate as the index of an acceleration effect depending on the number of processors and generates the list of executed results. Based on this list, an execution performance predicting means 4 executes performance prediction corresponding to any prescribed model and a calculation procedure. The predicted result is displayed by a display means 5.