Which date signifies when work on the supply should begin to meet the demand date?

The date that signifies when work on the supply should begin to meet the demand date is the start date. This is because the start date indicates the point in time when production or procurement activities must commence in order to ensure that all requirements are met by the demand date. It is crucial for planning and scheduling purposes, as it allows stakeholders to organize workflows, manage resources, and coordinate tasks effectively to ensure timely fulfillment of customer needs.

In contrast, the built date typically refers to when a product is actually manufactured or completed; the ship date indicates when the finished product is scheduled to be shipped to the customer, and the due date refers to when an order is expected to be delivered. These dates are associated with different aspects of the supply chain and do not serve as the trigger for initiating work to meet demand. Thus, the start date is essential for setting up a timeline to ensure that the supply is ready to fulfill demand.