A call tree, sometimes referred to a phone tree, call list, phone chain or text chain, is a telecommunications chain for notifying specific individuals of an event.
Call trees, which are an important component of every disaster recovery plan, are especially helpful if an organization needs to reach key personnel after hours to notify them of a problem. For a call tree to be successful, employee contact information must be up-to-date and individuals on the tree should supply multiple contact options. In the enterprise, a call tree can be automated with software that contacts individuals on the call tree, using technologies such as landline phone, email, pager, cell phone and Short Message Service (SMS) text message.
A call tree can also be carried out manually in a small or mid-sized business. In such a scenario, each person on the call tree contacts the next person on the list and that person contacts the next person (and so on) until everyone on the call tree has been reached. In the event that the next person on the list cannot be reached, the caller continues with the next level of the tree that so the chain does not break. To ensure that everyone who needs to know about the event has been notified, the last person on the call tree list should call the first person on the list to complete the loop.