When working from home the simplest approach is to simply divert your calls to another number. That way your calls to your office number can come through to your mobile. Another approach is setting up a simultaneous ring. This means that incoming calls will be received to all connected devices at once.
IVR is the concept of incoming callers to obtain information via a voice response system of pre-recorded messages without speaking to an agent, as well as use menu options by touch tone keypad selection.
Soft Phones are another good tool when working from home, have a look at our soft phone solutions here.