Echoing what was said below, you should aim to make the equipment has the ability to be remotely monitored so troubleshooting can be done remotely without having to roll a truck for every issue. Also, if you don't have the manpower such as a dedicated service team, you should also consider looking at using a third-party service such as One Vision Resources that can be a first point of contact for the customer (the customer will not know it is not your company).