My notion of the principle #5 “We believe that the customer is the only one capable to judge and evaluate the quality of our product” as follows.
It’s crucial to understand what makes customers happier and solve their needs. In most cases they’re interested not in the software we’re building but their problems to be solved. Hence we should all be on our guard not to get too excited about our product and start doing the work which we shouldn’t be doing, work which not help us to achieve the customer’s goal.
So how we can test our hypothesis here? We need to find out customers’ priority to make the software better. Sometimes customers care about bugs and sometimes not. Thus sometimes we may need to sacrifice quality by delivering value.
We need to have input about what customer problem we’re solving and drive our team that direction. In other words, we need to continuously recenter the team around solving customer needs.