ISO/IEC 27001:2022 Annex A · Control 5.24

Information Security Incident Management Planning and Preparation: A Practical Implementation Guide

Build an incident capability before pressure, uncertainty and time-sensitive decisions arrive.

This control focuses on planning and preparing processes, roles and resources for effective information security incident management.

Practical interpretation: An incident plan is valuable only if people can execute it. Preparation includes authority, playbooks, communications, tools, evidence, suppliers and exercises.

What should the control achieve?

Incident roles and decision authority are clear.
Events can be reported and triaged consistently.
Playbooks and communication routes are ready.
Exercises drive measurable improvement.

Step-by-step implementation

Define the incident framework

Set scope, severity, phases, escalation and links to continuity, privacy and crisis management.

Assign roles

Name Incident Manager, technical, legal, privacy, communications and business responsibilities with deputies.

Prepare playbooks

Create concise actions for likely scenarios such as ransomware, data exposure and supplier compromise.

Equip the team

Provide secure communication, logging, forensic tools, contact lists and emergency access.

Coordinate third parties

Define insurer, legal counsel, forensic, regulator, customer and supplier paths.

Exercise and improve

Run scenarios, record gaps and track corrective actions.

What this could look like in practice

A company runs a quarterly tabletop using a cloud-account compromise. The team practices severity assessment, containment authority, evidence preservation, customer impact and regulatory decision-making. Actions are assigned and retested.

Activity	Practical implementation	Evidence
Reporting	Staff use a single channel with urgent escalation.	Report and ticket
Activation	Severity triggers named team and secure bridge.	Activation log
Playbook	Team follows scenario checklist while documenting deviations.	Incident timeline
Exercise	Observers record decisions and improvement actions.	Exercise report

Implementation evidence

Incident response plan
Severity matrix
Role and contact list
Playbooks
Communication templates
Tool readiness
Supplier arrangements
Exercise and action records

Useful metrics

Exercises completed
Incident roles with trained deputies
Exercise actions closed
Time to activate response team

Common mistakes

Writing a long plan nobody can navigate.
No authority for urgent containment.
Depending on compromised email for coordination.
Missing supplier and legal contacts.
Running exercises without closing findings.

Questions an auditor may ask

Who can declare an incident?
How are severity and escalation decided?
Show a tested playbook.
What improvements resulted from the last exercise?

Implementation test: Start an unannounced tabletop and measure whether the team can assemble, choose secure communication and make the first containment decision.

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This independent educational guide paraphrases the practical intent of the control and does not replace the official ISO standards, professional advice or an organization-specific risk assessment. It is not affiliated with or endorsed by ISO.

ISO 27001 Annex A 5.24: Information Security Incident Management Planning and Preparation – Practical Implementation Guide