A provisioning method for allocating a plurality of resources required by a plurality of services, including staging, so as to provide at least one stage, as an intermediate state, in the process of provisioning, in a resource pool shared by the plurality of services. A state of at least one of the plurality of resources is allocated to at least one of the stages as an initial state provided in advance. A predetermined cost is calculated by using a predetermined algorithm based on a setting operation time required for causing a state of each of the allocated plurality of resources to transition to another stage, and optimally allocating all the plurality of resources to the respective stages in order to minimize the predetermined cost.