You can configure a service as Blocked here. You cannot register new orders for a blocked service in any of the order modules. This will not affect orders on hand and you can still perform regular reporting on orders on hand as usual.
When you check the "Blocked" box, the date and name of the person who blocked the service will appear in red font below the check box. A button appears which can be used to enter why the service was blocked. The cause entered here will be displayed when you try to register orders for a blocked service.