RTO (Recovery Time Objective) and RPO (Recovery Point Objective) are two important concepts in disaster recovery planning. Both refer to the maximum acceptable time and data loss in the event of a disruption, but they measure different things.
What is RTO?
RTO stands for Recovery Time Objective. It is the maximum acceptable length of time that a business process or service can be down after a disaster occurs. RTO specifies how quickly systems, applications, or functions must be restored for normal operations to resume.
RTO is measured in time, such as hours, days or weeks. A lower RTO means less downtime is acceptable to the business. For example, an RTO of 24 hours means that systems must be restored within 24 hours after an outage or disruption.
Some examples of RTOs for different systems:
- Critical systems like ERP or e-commerce – 1-4 hours
- Important backoffice systems – 24-48 hours
- Internal tools and applications – 72 hours or more
The RTO is agreed upon by business leaders and IT teams based on how long the business can tolerate the system being unavailable before unacceptable impacts occur, such as revenue loss, legal/regulatory breaches, reputational damage, etc.
What is RPO?
RPO stands for Recovery Point Objective. It refers to the maximum amount of data loss or transaction loss that is acceptable in the event of an outage.
RPO is measured based on time, such as minutes, hours or days. It represents how far back in time you need to recover data and transactions to before the disruption occurred.
Some examples of RPOs:
- Database systems – 15 minutes
- File backups – 24 hours
- Archive data – 7 days
The RPO is determined based on the sensitivity of data and how current it needs to be after recovery. A lower RPO means less potential data loss is acceptable.
Differences Between RTO and RPO
While both RTO and RPO refer to business continuity concepts, there are some key differences:
- What they measure – RTO measures downtime or system unavailability, while RPO measures data loss.
- Scope – RTO is focused on business processes and services, while RPO is focused on data.
- Measurement – RTO measures elapsed time from an outage, while RPO measures point in time for recoverable data.
In simple terms:
- RTO – How long until systems are restored?
- RPO – How much data can we lose?
Is RTO Higher Than RPO?
Generally, yes – RTO is often higher than RPO. There are a few reasons for this:
- Restoring systems and functionality takes more time than just recovering data to a point in time.
- Data recovery mechanisms like backups and snapshots allow for low RPOs, since data can be rolled back in smaller increments.
- The business impact of long downtime is usually deemed worse than some data loss.
However, it depends on the specific systems and data being considered. Here are some examples:
| System | RTO | RPO |
|---|---|---|
| CRM platform | 24 hours | 1 hour |
| Email servers | 4 hours | 15 minutes |
For the CRM platform, RTO is higher since restoring the whole application functionality could take up to 24 hours. But only 1 hour of data loss is acceptable.
For email servers, the RTO is lower at 4 hours since email is a critical business function. But there can be up to 15 minutes of email data loss.
In some cases, RPO could be higher than RTO. Examples:
- A cache that can be restored instantly (RTO minutes), but caching interval is hourly (RPO 1 hour).
- An archive database with low uptime requirements (RTO days) but storing legal data requiring 14 day retention (RPO 14 days).
Factors That Determine RTO and RPO
Some key factors that influence RTO and RPO targets include:
Business criticality
More critical systems and data require lower RTO and RPO. Losing key systems like e-commerce for an extended time or sensitive data like financial transactions will have bigger business impacts.
Architecture
Systems and data architectures affect recovery abilities. Highly redundant infrastructure with effective backups allows lower RTO and RPO.
Recovery mechanisms
The available recovery tools and processes directly impact RTO and RPO. For example, server snapshots allow faster recovery than full server rebuilds.
Costs
Lower RTO and RPO capabilities often require additional investments in resilience. There are tradeoffs around cost vs. reducing downtime and data loss.
Regulatory compliance
Industry regulations can impose maximum downtime and data loss requirements that dictate RTO and RPO.
Relationship Between RTO and RPO
While RTO and RPO refer to distinct concepts, they are dependent on each other in business continuity planning:
- The RPO must be lower than the RTO to prevent data loss after recovery.
- A lower RTO requires mechanisms to support a lower RPO, like highly frequent backups.
- Long RTOs may require higher RPOs to stay within outage duration limits.
- Short RTOs force lower RPOs to prevent data gaps after systems are restored.
Aligning RTO and RPO is necessary for coordinated business continuity. Short RTOs without adequately short RPOs mean restored systems lack current data. And lower RPOs without fast enough RTOs lead to extra data loss during prolonged outages.
Best Practices for Setting RTO and RPO
Here are some best practices around defining RTO and RPO:
- Set RTO and RPO based on in-depth business impact analysis of downtime scenarios.
- Validate that the RPO supports achieving the RTO – data recovery time must be shorter.
- Review technical capabilities to meet target RTO and RPO with reasonable costs.
- Test recovery plans regularly to confirm RTO and RPO are being met.
- Adjust RTO and RPO as business requirements evolve over time.
- Define RTO and RPO at granular levels for individual systems and datasets.
- Communicate RTO and RPO expectations clearly across business and IT teams.
Measuring and Reporting on RTO/RPO
Ongoing tracking and reporting of RTO and RPO metrics provides visibility into whether business continuity requirements are being satisfied:
- RTO reporting – Track and analyze system downtime incidents to compare against RTO standards.
- RPO reporting – Measure against RPO through mechanisms like recovery point testing and snapshots.
- Automation – Use business continuity tools to automatically compile metrics on RTO and RPO performance.
- Dashboards – Display key RTO/RPO indicators on centralized dashboards for visibility across teams.
- Non-compliance alerts – Trigger notifications for outages or data loss exceeding defined RTO/RPO limits.
Ongoing RTO and RPO reporting provides assurance that recovery capabilities are meeting business continuity needs. It also highlights any gaps that require improvement.
Conclusion
In most cases, RTO exceeds RPO – recovery time is longer than data loss tolerance. However, the specific relationship depends on the systems, data, and downtime impacts involved. RTO and RPO must align to deliver coordinated business continuity through both restored services and current data.
Rigorous RTO and RPO standards based on business needs, combined with robust reporting, gives organizations confidence they can recover from disruptions within acceptable windows.