Glossary · Business continuity
Maximum Tolerable Period of Disruption (MTPD)
The longest time an activity can be unavailable before the resulting harm to the organization becomes unacceptable.
What the MTPD is
The Maximum Tolerable Period of Disruption is the outer limit of downtime an organisation can survive for a given activity. Beyond it, the consequences threaten the viability of the organisation or breach legal and contractual obligations. ISO 22301 defines it as the time it would take for the adverse impacts of not performing an activity to become unacceptable; some standards call the same limit the maximum acceptable outage (MAO), and BSI Standard 200-4 uses maximal tolerierbare Ausfallzeit (MTA).
How it is set
The MTPD is a business decision, not a technical one. In the business impact analysis the process owner rates how the damage grows over hours and days: lost revenue, penalties, harm to people, regulatory deadlines, reputation. The point at which that damage becomes unacceptable is the MTPD. It often differs by season or time of day: a payroll run at month end tolerates less than the same process mid-month.
How it relates to RTO and RPO
- The RTO must always be shorter than the MTPD, leaving a margin so recovery completes before tolerable limits are exceeded.
- The RPO comes from the same analysis but answers a different question, namely how much data may be lost.
- Processes with the shortest MTPD recover first; the MTPD therefore sets the recovery order across the organisation.