  Experiments such as mu2e (FNAL, USA) and COMET (KEK, Japan), seeking the
direct muon-to-electron conversion as part of the study of Charged Leptons
Flavor Violation processes, should have a extremely high, up-to 99.99\%,
efficiency muon detection system with a view to their subsequent suppression as
background. In this article, the possibility to achieve such efficiency for a
short and long term is discussed for modules based on 7- or 10-mm-thick but
same 40-mm-wide plastic scintillation strips with single 1.2 mm WLS fiber glued
into the groove along the strip and using MPPC/SiPM for light detection.
  A Simplified Light Yield Distribution method to estimate the efficiency of
the module was proposed and the simulation results obtained with GEANT 4 for a
system based on a 4-by-4 array of 7x40x3000 mm strips compared with the
experimental data. Found that for the systems required the high level
registration efficiency at the 99.99\% and more, it is important to improve the
light yield as much as possible and achieve the gap between neighbor
scintillation volumes as small as possible.
