What is an example of a quantified requirement in a CTQ tree for an auto repair shop?

A quantified requirement in a Critical to Quality (CTQ) tree is a specific measurement that indicates the desired level of performance or quality for a particular aspect of the service or product. These requirements are essential in understanding what the customers value most and how those values can be translated into measurable criteria.

The option of having a wait time for pick-up not exceeding 30 minutes serves as a clear, quantifiable standard. This requirement is directly measurable and time-bound, which allows the auto repair shop to assess its performance against this target. Customers expect timely service, and by establishing an explicit maximum wait time, the shop can strive to meet or exceed this expectation, subsequently improving customer satisfaction.

In contrast, the other options present more subjective criteria or do not provide specific measurable targets. For instance, a clean waiting room may be important for customer perception, but it lacks a measurement standard. Similarly, an accurate and detailed bill is essential for clarity in customer transactions, but it doesn't specify what 'accurate' means in terms of quantifiable metrics. A well-stocked vending machine holds value for customer comfort but does not translate into a measurement that can be applied across all customer experiences. Thus, the option concerning wait time stands out as the only one that offers a concrete