Little errors can have a big impact. This article about small cracks in the Airbus 380 is a good example for that. As a customer I expect quality. So don't come back to me with excuses why something doesn't work or even worse try to hide it.
Be open with what went wrong otherwise I will lose trust. This happens especially quickly with things that are potentially life threating (e.g. medical devices, airplanes etc) . Come back with a short, understandable plan on how you plan to fix it. Once it is fixed then make sure that I understand what you did do that I (as the customer) have a chance to appreciate it.
Doesn't that very much sound like good Project Management Practices?
