A Single Point of Contact
Some of my clients themselves have customers to whom I provide a troubleshooting service. In such cases, I am seen by the customer as the supplier, and I provide a complete service as if I am that supplier. This frequently involves identifying and resolving issues that have nothing to do with the system that I built for my client. Examples include
In all cases, I explain the issues to the customer and agree a plan of action. This usually means consulting third parties to rectify the issues under their control, and communicating the agreed actions and timescales to the customer.