A management server which manages a tenant pattern being information for forming a tenant being an application system for executing a predetermined application by using computer resources within a computer system, the tenant pattern including a configuration item and an ID pool, the management server having: pattern parts information for managing the configuration item as a pattern part that forms the tenant pattern; validation rule information for storing a detail of validation processing for a composition of the tenant pattern; and the management server further comprising: a tenant pattern generation unit; a tenant designing unit for designing a composition of the tenant, and generating a configuration detail for actually building the tenant on the computer system; and a validation execution unit for executing the validation processing for the tenant pattern and the configuration detail based on the validation rule information.