Tier 1: Help desk operators provide general directory information and route incoming calls to first line support or support queues.
Tier 2: Majority of cases resolved by first line support, who close case and update with documentation of the solution to allow other support to reference in the future. If the issue needs to be escalated, it will be updated, noting what was attempted by the first level support and dispatched to second level support.
Tier 3: Second Line support is formed of product engineers/developers or highly skilled technical support staff of the product.