Abstract: The number of man-hours is reduced for constructing a digital twin with a digital twin cooperation system that causes a business system related to production including product manufacturing to cooperate with a digital twin for simulating the production based on transaction data and model data. The result data related to the production acquired from the business system is converted into the transaction data using the master data and inputting the transaction data into the digital twin. Included are a change detection step of detecting a change in manufacturing information related to the product manufacturing that the business system has; a determination step of determining whether the change is absorbable in the master data based on an existing record of the master data; and an update step of updating the master data or the model data based on the change according to a determination result of the determination step.