"In retail, CTS measures the cost of all aspects of delivery (fulfillment centers, deliveries, returns, compute costs, software) divided by the total number of units fulfilled to customers (where each unit is a purchased item). Reducing CTS drives improvements across many dimensions of the supply chain, including delivery frequency, speed, friction, and quality. Removing delays reduces CTS. Delivering items together reduces CTS. Reducing defects and returns reduces CTS.
Similarly, CTS-SW measures the total cost of delivering a unit of software.”
https://aws.amazon.com/blogs/enterprise-strategy/business-value-of-developer-experience-improvements-amazons-15-9-breakthrough/?__readwiseLocation=