Digital lock installation or Repair

What is OOS in this Case?
Digital Lock Repair is an OOS Case- Reversible Case

What is not OOS Case?
Native Lock Repair is not an OOS Case- Non-Reversible Case
Digital Lock Installation is not an OOS Case- Non-Reversible Case

Single line crisp description - Why this has to be OOS?
Partner can install digital bell but can't repair skill issue