What is MTD and why it matters for businesses
- MTD (Maximum Tolerable Downtime) is the longest time your business can accept a process, service, or system being down before it causes serious impact.
- It’s the point where an outage becomes unacceptable—leading to financial loss, compliance/legal issues, reputational damage, or safety risks.
Examples of maximum tolerable downtime for common business processes
- Electric power - MTD 2 minutes (almost everything stops without electricity)
- Customer support – MTD 4 hours (issues pile up fast and customer trust drops)
- Cleaning services - MTD 3 days (short outages are usually manageable)
- Document archive – MTD 7 days (short outages are usually acceptable)
Example MTD tiers
- 0–4 hours (immediately critical)
- up to 24 hours
- up to 72 hours
- up to 7 days
In short: MTD = the maximum acceptable downtime for a process before major damage occurs.
What is recovery time?
- Recovery time is measured from the start of the outage until the process is running again (or a workable workaround is in place).
- Recovery time must fit within the outage window (MTD is always longer than RTO).
- Set RTO (Recovery Time Objective) below MTD — so you restore the system before the downtime becomes critical.