The MPI Load Balance Efficiency (MPI LBE) describes the distribution of work in MPI processes only considering time outside MPI.
It can be expressed in terms of Hybrid Parallel Efficiency (HPE) and Hybrid Communication Efficiency (HCE):
\[MPI\_LBE = \frac{HPE}{HCE} = \frac{ \frac{\sum_{(i=1)}^POutsideMPI_{i,1}}{P} } { Max(OutsideMPI_{1,1}, \cdots, OutsideMPI_{P,1}) }\]Where:
In order to fully understand the formulas, you may also visit the glossary of the metrics terms.