Something to guard against: extensions on extensions on extensions.
In years past, CA closures were prolonged (resource constraints, interest...the usual suspects). It got easy for folks to ask for an extension and then close something out a day or two later. Metrics improved but of course (CAPAs done within our arbitrarily set 30 days, yada-yada) but didn't tell the whole story. I ended up creating a second metric to track the number of extensions given. This curbed padding a number while allowing another to run away. Sad it had to happen that way.
OK - where's my soap box?
Deming warned about setting Goals without a Method. Lloyd Nelson also warned that the most important numbers are unknown and unknowable. Both agreed that abstaining from managing a process because a 'hard' number could not be established was not an answer either. When establishing 'hard' numbers, folks must be intimate with the process, understand control limits and process controls before setting them. Otherwise, numbers are arbitrary and usually end up causing more trouble than you would have had without them. Managing a process, CA (CAPA) or otherwise, requires theory and knowledge of the process. Statistically speaking, is there a difference between 75% and 85%? Examining the process closely might reveal that either exist between the control limits - no difference (each had the equal chance to appear). What happens is that folks kick off the new year with new 'numbers'. Business folks are infamous for doing this. What's needed is appropriate goal setting under the conditions Deming and Nelson suggest. In a nut shell, forget the goal setting and manage the process. Show auditors this kind of data, this level of intimacy, and you won't have to argue much at a closing meeting
Good luck everyone!