“The supplier is responsible for the quality of his or her product or service”.
This is impossible because the customer is always involved in the service or product. The customer makes use of it.
“We expect our suppliers to improve their performance year on year”.
For example reduce costs, improve quality; improve on our supplier evaluation system.
This is usually manifest as a squeeze on suppliers – in an attempt to reduce costs. In some cases it is no more than shafting suppliers. Many organisations employ ‘professional procurement’ people whose job it is to bully suppliers.
The better way is to work in co-operation with suppliers, so both parties win and the common system improves.
This is to treat the supplier as part of your system and to work with suppliers over the long term. Working in cooperation means you can get rid of costly and unhelpful procurement ‘professionals’.