A system includes: circuitry configured to receive a condition regarding a constraint condition of a product, acquire past requirement values for the product, predict, for each of a plurality of periods, requirement value for the product by calculating the requirement value for each of the plurality of periods based on the acquired past requirement values, generate, based on the predicted requirement value for each of the plurality of periods, a probability distribution of the constraint condition for each of a plurality of requested arrangements each of which indicates requested quantities of the product for each of the plurality of periods, and output at least one of the plurality of requested arrangements, based on the generated probability distribution and the received condition regarding the constraint condition.