In this paper inventory model of declining goods with ambiguous and imprecise details about available storage has been established. Here, our targets are: 1- the optimal scheduling period, 2- the optimal order-level, 3- minimize the wastage cost due to the deterioration, 4- minimize the expected average total cost under a restriction on the expected average varying deteriorating cost by using the Lagrange method. This model, is developed for continuously deterioration rate is constant or follows a two-parameter Weibull distribution with varying and constrained expected deteriorating cost, Where the lead time is only one period of time, without shortage and when demand is a random variable during any scheduling time. These probabilistic models are studied in two cases: crisp numbers and trapezoidal fuzzy numbers. Some special cases are deduced. There is a numerical illustration to illustrate the proposed model in the crisp case and the fuzzy case and the sensitivity analysis is performed.