In July the phone rings while every tech is on a roof, and the caller with no air conditioning does not leave a voicemail; that call goes to the next company on the list. MairyAI answers it on your own number, states that the caller is speaking with an AI assistant, finds out what is wrong, and books the service visit into the calendar your dispatcher already uses.
Every call ends in writing: what failed, when it started, the address, the system if the caller knows it, and what was booked. Emergencies can go straight through to your on-call tech under rules you set. You read the record in the morning instead of returning calls to people who have already hired someone else.