1. A method of scheduling manufacturing of a product by a requested availability date, the method comprising: selecting sources of supply from a database stored on a storage device for multiple components to be used for manufacturing the product; checking by a computer system if valid-to dates of the sources of supply extend at least to a plan start date; calculating by the computer system lead times for sources of supply having a valid-to date extending at least to a plan start date; selecting a source of supply as a function of a validity interval and a validity date, wherein the validity interval corresponds to an intersection of validity intervals of individual components determined from scheduled engineering changes to the manufacturing of the product and the validity date is determined as a function of the requested date and time to transfer the manufactured product to a consumer; exploding a bill of materials corresponding to the multiple components with an explosion date within the validity interval: receiving a scheduling change for manufacturing of the product; determining a new explosion date based on the scheduling change; and re-exploding the bill of materials based on the scheduling change only the new explosion date is outside the validity interval.