The ITSM Professor addresses a recent question he was asked concerning a good metric for first call resolution (how often the help desk is able to get a user's problem resolved in the first call). He recognizes that it's a tricky question: there isn't necessarily a defined percentage to aim for, and even ITIL is a bit hazy on what a good percentage, though industry experts have a general goal:
While ITIL acknowledges FCR as an important Service Desk metric, it steers clear of offering a target or benchmark. Industry experts generally accept a FCR range of 65 to 80 % Despite this, I would recommend avoiding a “one size fits all” approach and instead suggest that you map FCR targets to your high level incident models. Requests and standard changes might be expected to exceed 90% FCR. Major incidents would likely have a very low FCR target until a trusted workaround is identified and deployed. In this way, the message behind the metric is situational and clarifies opportunities for specific improvements.
the blog post goes on to explain that there is a fine line between creating too many or to few FCR goals: if you have too many, the metric may become meaningless. Too few and the measurement will become to hard to achieve, or too generic to be anything more than another number in a report.