Which of the following statements is true?

The assertion that a part has one and only one part number is fundamental to inventory management and manufacturing processes. A part number serves as a unique identifier for a specific item in a company's inventory system. This unique identification helps maintain clarity and accuracy in inventory records, facilitating everything from procurement to production planning.

Having a single part number ensures that when a particular item is referenced, there is no confusion with similar or related products, which could lead to errors in ordering, fulfillment, or production. This systematization is crucial for efficient supply chain management, allowing organizations to track inventory levels accurately, streamline operations, and reduce the likelihood of costly mistakes.

The other statements present scenarios that disrupt this clarity and uniqueness. For instance, using the same part number for similar products could lead to confusion, while having different numbers for the same part across various bills of materials could complicate inventory tracking and management. The statement regarding an item being either a parent or a component but not both suggests a limitation that is not representative of real-world manufacturing practices, where the same item can serve multiple roles in different contexts.