The Hybrid Parallel Efficiency (HPE) meassures the percentage of time outside the two parallel runtimes.
As in the original MPI model, this efficiency can be split between two components: the Hybrid Load Balance Efficiency (HLBE) and the Hybrid Communication Efficiencies (HCE); or it can also be expressed in terms of MPI Parallel Efficiency (MPI PE) and OpenMP Parallel Effienciency (OpenMP PE):
\[HPE = HLBE \times HCE = MPI\_PE \times OpenMP\_PE\]In order to fully understand the formulas, you may also visit the glossary of the metrics terms.