  The long-term variation of the H$\alpha$ line in $\alpha$ Eri has 14-15 years
cyclic \bbe phase transitions. The disc formation time scales, interpreted as
the periods during which the H$\alpha$ line emission increases from zero to its
maximum, agree with the viscous decretion model. On the other hand, the time
required for the disc dissipation ranges from 6 to 12 years which questions the
viscous disc model predictions.
