Which of the following is NOT included among the five zeros?

The correct choice identifies an option that does not belong to the commonly recognized framework of the 'five zeros' in quality management and operational excellence. The five zeros typically refer to key performance metrics aimed at minimizing waste and maximizing efficiency, which include concepts such as zero defects, zero handling, and zero lead times.

Zero defects emphasizes the importance of producing goods and services without any defects, thus improving quality and reducing rework. Zero handling refers to the goal of eliminating unnecessary movements and handling of materials, which streamlines operations and reduces labor costs. Zero lead times focuses on minimizing the time it takes to complete a process or deliver a product to customers, thereby enhancing responsiveness and customer satisfaction.

While zero customer complaints might seem relevant to customer satisfaction, it is not one of the established five zeros. Instead, it is a byproduct of achieving the other zeros but does not specifically represent a goal of operational processes in the way the other choices do. This distinction helps clarify the focus on operational efficiencies rather than just customer feedback metrics.