The order defect rate on Amazon is an indicator to measure the seller's ability to serve the buyer. It includes

Amazon mall transaction guarantee claim rate

This indicator is the claim order in a period of time divided by the total number of orders in that period of time.

Negative feedback rate

This indicator is the number of negative feedback (bad reviews) in a period of time divided by the total number of orders in that period of time.

Service credit card rejection rate

This indicator is the number of credit card rejections in a period of time divided by the total number of orders in that period of time.