Quality metrics are measurements that are used to evaluate the value and performance of products, services, and processes. These metrics can be used to identify areas for improvement and to ensure that products and services meet the needs and expectations of customers and stakeholders. Quality metrics may include measurements of functionality, reliability, usability, efficiency, and customer satisfaction, among others. By tracking and analyzing quality metrics, organizations can improve the quality of their products and services and better meet the needs of their customers. The following are common examples.

Customer Satisfaction
In many cases, it is appropriate to measure the quality of a product or service by the quantifying customer opinions. The most common way to do this is simply to ask customers to rate their satisfaction. For example, there is no better way to measure the quality of a meal beyond asking the customer if it was good.

Ratings
Ratings of products and services such as those offered by reputation systems.

Failure Rate
The reliability of products as measured by the probability of a failure over a period of time. For example, a robot might have an annual failure rate of 0.1% indicating that 1 out of 1000 units fail in a year.

Mean Time Between Failures
The reliability of IT services is often measured as the mean time between failures. For example, a software service with a mean time between failures of 6 months is down twice a year on average.

Quality of Service
Quality of service is a telecom industry term for the quality of network services such as internet connectivity measured using technical metrics such as error rates, bit rate, throughput, transmission delay and availability.

Quality Control
Quality control is the sampling or testing of manufactured units or delivered services. For example, a hotel might randomly sample rooms that have been cleaned to make sure that the room is in the expected condition. This can then be tracked as a quality metric such as the percentage of rooms that met the hotel’s standards.

Defect Rate
The quality of processes or project work can be measured with a defect rate. For example, the number of defects per 1000 lines of code can be considered a quality metric.