Every ticket that comes into the helpdesk is ‘open’ by default. It is the first stage of the ticket lifecycle and it is an indication that the customer’s problem hasn’t been solved.
When an open ticket is assigned to an agent, there are two paths it can embark on. One, the agent is able to figure out the solution to the problem and change the ticket status to ‘Resolved’ immediately. Two, they need more information before they can solve the problem, either from customers or from other teams. Depending on the situation, the agent changes the status of the ticket.
Open is the default status of a ticket; a status for which the SLA timer is on. So, open tickets should be taken up and responded to (and resolved) within the due by time.