In the paper approximate formulas for the mean waiting times and the buffer dimensioning in the system with vacations fed by the stream of Poissonian type with constant service times is shown. Furthermore. in the considered system the time intervals of the availability/notavailability of the service are constant and are run alternately according to the assumed cycle. More precisely. https://chefesquipmenters.shop/product-category/food-serving-pails-buckets/