Disaster recovery planning: how to build and test a workable plan

A workable disaster recovery plan is not a general document for “when something goes wrong”. It is a tested sequence for restoring named services within agreed RPO and RTO targets. It defines activation criteria, dependencies, roles, technical procedures, communication and evidence that recovery succeeded.

Backups are only one input. If nobody knows who declares a disaster, which systems come first or how data integrity is validated, having a copy does not guarantee a return to business.

What a DR plan must answer

A disaster recovery plan needs practical answers to six questions:

1. Which processes and systems recover first?
2. How much data loss is tolerable?
3. How long may each service remain unavailable?
4. Where are copies, configuration, secrets and standby resources?
5. Who makes decisions and performs the procedures?
6. How will the organisation prove that a service is usable, not merely running?

NIST SP 800-34 Rev. 1 provides a useful contingency-planning structure: business impact analysis, recovery strategies, plan development, testing, training and maintenance. Treat it as a framework to adapt to your architecture and applicable obligations.

Begin with business impact, not servers

A Business Impact Analysis connects downtime to consequences. Record the business process, owner, peak periods, supporting systems, temporary manual workaround and how the impact grows over time.

Priority	Example process	Planning question
Critical	Identity or payment	How can it recover without compromising integrity?
High	Orders or customer notifications	How will queued work be reconciled?
Medium	Internal reporting	Can a temporary manual process operate?
Low	Archive access	Can recovery wait?

Declaring every system critical removes any meaningful order and makes standby infrastructure unnecessarily expensive.

Align RPO and RTO

RPO describes tolerated data loss measured in time. RTO describes tolerated time to restore the function. A business owner and IT should agree on both; they are not purely infrastructure settings.

Test the objectives for internal consistency:

• backup or replication frequency can satisfy the RPO;
• detection, decision, startup and validation all fit inside the RTO;
• dependencies have targets at least as strong as their consumers;
• recovery has enough network and storage throughput;
• licences, DNS, certificates and secrets exist in the recovery environment.

Our guide to backup and fault tolerance explains RPO/RTO and the difference between data protection and high availability.

Dependencies determine recovery order

A service rarely recovers alone. It may rely on DNS, identity, a database, message broker, storage, a partner API and a notification channel. For every dependency, record:

• technical purpose and owner;
• acceptable degraded mode;
• availability check;
• alternative route;
• maximum wait time.

Express the recovery order in waves: core network and access control, data services, shared platforms, critical applications, integrations, and then non-critical services. In IaaS, document the line between provider and customer duties; the trade-offs are described in IaaS versus an owned data centre.

Structure of an executable runbook

Give every critical service a concise procedure that an on-call engineer can follow.

Activation

• observed symptom and confirming source;
• threshold for declaring a disaster;
• role authorised to initiate failover;
• risk of continuing in the primary environment.

Recovery steps

• exact commands or links to automation;
• expected outcome of each step;
• safe stopping point;
• rollback when a step fails;
• method for obtaining credentials without embedding them in the document.

Validation

• technical health checks;
• integrity and freshness checks;
• an end-to-end business transaction;
• acceptance by the process owner;
• decision to restore traffic.

Return to primary

Failback can be harder than failover. Data changes need reconciliation, the cutback needs an approved window, dual writes must be prevented, and the service needs another validation.

Roles and communication

The minimum useful team includes an incident commander, technical owners, a communication coordinator and a business representative. One person should not be expected to execute every technical action while also setting priorities.

Prepare message templates for staff, customers and partners. Each update should state confirmed impact, the current mitigation, the time of the next update and the support path. Avoid promising a restoration time before the recovery team has validated it.

Contacts and the plan itself need an access path that survives the outage of the main collaboration suite. At the same time, network diagrams and access procedures require version and permission controls.

Testing the plan

Increase exercise risk gradually:

1. Tabletop: stakeholders reason through a scenario.
2. Walkthrough: owners follow the runbook and validate access.
3. Component recovery: one database or service is restored.
4. Partial failover: part of a real workflow moves to standby.
5. Full exercise: an approved critical environment is recovered.

Measure actual RPO and RTO, manual-step count, access failures, decision time and validation coverage. Booting a virtual machine does not prove that a business process recovered.

Connect exercises to infrastructure observability: alerts should discover the scenario, while metrics and traces confirm that recovery worked.

Common gaps

• A copy exists, but nobody has tested a restore.
• The document names individuals instead of roles and on-call contacts.
• The only secret or MFA path depends on the failed system.
• Queued work and replay are absent from the plan.
• Nobody owns the failover or failback decision.
• A dependency has a weaker RTO than its consumer.
• Architecture changed but the runbook did not.
• Recovery validation stops at ping or HTTP 200.

Document checklist

• Scope and version.
• Plan owner and next review date.
• Activation and completion criteria.
• BIA, priorities, RPO and RTO.
• Dependency map and recovery waves.
• Roles, contacts and escalation.
• Runbook for each critical service.
• Internal and external communication channels.
• Integrity checks and business acceptance.
• Exercise history, findings and corrective work.

Review the plan after a major migration, data-model change, provider change, identity redesign or integration rollout. During a cloud move, use the IaaS migration plan as a current source for dependencies and acceptance criteria.

Next step: Logic Telecom can help inventory dependencies and design a DR exercise programme. A practical starting point is to recover one critical service in an isolated environment and compare the observed result with its declared RPO and RTO.