Final answer:
True. Level I mistake proofing devices, or poka-yoke devices, are designed to prevent problems at their source, such as using a three-pronged plug that can only fit into a socket one way.
Step-by-step explanation:
The statement is true. Level I mistake proofing devices are also known as poka-yoke devices in the Lean manufacturing process. Their primary function is to prevent errors by designing systems that make it impossible to commit a mistake in the first place. A classic example is a three-pronged plug that can only be inserted into a socket one way, thus preventing the problem of electrical misconnections at its source.