Define the ending event
A closed status is easy to count but may reflect a timeout, duplicate merge or team cleanup rather than a solution. Choose the resolution evidence for each intent: an answered policy question differs from an account action awaiting confirmation. Record the closure reason. If you use system status as a proxy, disclose that limitation instead of describing every closure as a verified customer outcome.
Keep waiting time visible
Separate active handling, internal waiting and waiting for the customer where your records allow it. Do not silently remove slow unresolved cases from the report; list their count and age separately. Decide whether reopening resumes the original clock or starts a new interval, and retain that definition across languages and reporting periods.
Fictional worked example
Fictional case: opened Monday at 10 AM, waiting for an internal decision until Tuesday at 10 AM, then closed at noon. Elapsed resolution time is 26 hours, even if active handling took only 30 minutes. Both measurements can be useful, but they answer different questions. An unresolved case still open on Tuesday should appear in the backlog, not disappear from analysis.
Action checklist
- Define the evidence or proxy used for resolution.
- Retain closure reasons and a consistent reopening rule.
- Separate elapsed time from active handling when possible.
- Report open-case age beside completed-case resolution time.