ISO9001 requires that one of the measurements that must be made is to monitor information relating to customer perception as to whether a company has met customer requirements, ie customer satisfaction. This can be done by looking at;
- customer satisfaction surveys,
- data on delivered product quality,
- user opinion surveys,
- lost business analysis,
Note the word perception which requires a company to find out what customers think of them. There might be no visible issues with a customer as deliveries are on time and there are no returns or complaints. But it is possible that a customer finds customer service to be poor or lead times are too long. The products and services meet their requirements but if another company who can provide better service the customer would be off.
This information needs to be looked for it is not going to just appear.