  We propose a scenario for a periodic filling and emptying of the accretion
disc of GRS 1915+105, by computing the mass transfer rate from the donor and
comparing it with the observed accretion rate. The binary parameters found by
Greiner et al. (2001) predict evolutionary expansion of the donor along the
giant branch with a conservative mass transfer rate (1 - 2)E-8 solar masses per
year. This reservoir can support the present accretion with a duty cycle 0.05 -
0.1 (the active time as a fraction of the total life time). The viscosity time
scale at the circularization radius (15 solar radii from the primary 14 solar
mass black hole) is identified as the recurrent quiescent time during which a
new disc is formed once consumed by the BH. For small viscosity (alpha = 0.001)
it equals to 300 - 400 years. The microquasar phase, with the duty cycle, will
last around 10 million years ending with a long period black hole + white dwarf
system.
