1. A computer-executable method for determining an allocation configuration for allocating virtual machines to physical machines, the method comprising the steps of: determining a total predicted peak usage amount of physical resources based on the sum of predicted peak usage amounts for each time interval of a plurality of time intervals for individual clusters of a plurality of clusters wherein the clusters include a plurality of virtual machines; setting a constraint that ensures that, for individual combinations of a first physical machine, a second physical machine, and a time interval t, the total predicted peak usage amount of the physical resource predicted for the first physical machine if the second physical machine stops during the time interval t does not exceed the physical resource amount prepared for the first physical machine, wherein for the first physical machine k, the second physical machine k′, and the time interval t, for which the total predicted peak usage amount is predicted, and the setting step comprises the step of formulating the total predicted peak usage amount Φ k,k′,t as the sum total of the predicted peak usage amount γ c,t of clusters c, predicted for the first physical machine k if the second physical machine k′ stops, the peak usage amount γ c,t ; and deriving an allocation configuration by calculating, in accordance with the constraint, a solution to an optimization problem for minimizing, as an objective function, the sum total of the physical resource amounts of the plurality of physical machines to which the virtual machines are allocated.