RTO, RPO and MTPD: three values, three different decisions

What does MTPD mean?

MTPD stands for Maximum Tolerable Period of Disruption. It is the span after which the consequences of an outage become unacceptable for the organisation, because contractual deadlines lapse, legal obligations are breached or the damage threatens its survival. BSI Standard 200-4 uses the term maximal tolerierbare Ausfallzeit (MTA) for the same limit.

The business side sets the MTPD per business process in the business impact analysis. It is not a technical figure but the boundary from which RTO and RPO are derived: the RTO has to sit well before the MTPD so that recovery completes with a margin.

The terms must not be interchangeable

The maximum tolerable period of disruption sets the business limit. The RTO sits before it and describes the recovery target. The RPO answers a different question: which state of the data must it be possible to return to?

Targets must fit together technically and organisationally

An RTO of four hours is worthless if decisions, alternate workplaces or supplier commitments only become available after a day. Requirements are therefore checked against existing capabilities and documented as gaps.

• Check the business target time against the technical recovery time
• Reconcile data loss tolerance with the backup and replication concept
• Recover dependent services in the right order