Which of the following is not one of the six key dates in the planning horizon?

The completion date is not one of the six key dates typically recognized in the planning horizon. The six key dates are generally focused on the various stages of the planning and fulfillment process, including when tasks must start or be completed, and when materials or products need to be shipped to meet customer expectations.

The start date signifies when an operation or task is set to begin, allowing planners to schedule resources and allocate efforts accordingly. The ship date is crucial for logistics and supply chain management, as it indicates when a product will be dispatched from the facility. The due date represents the deadline by which a product or service must be delivered to the customer, ensuring that commitments are met.

In contrast, while the completion date might be a relevant term in certain contexts, it does not fit into the established framework of key dates that guide planning and execution in supply chain management. Understanding this distinction helps clarify the critical timings required for effective planning and customer satisfaction.