An information security management system (ISMS) is the keystone of the ISO 27001 standard. The framework is built to provide guidance for building, assessing, maintaining, and improving a secure ISMS.

Below, we’ll unpack what an ISMS is and explain how to build one that meets the requirements of the current ISO/IEC 27001:2022 international standard.

What is an Information Security Management System? (ISMS)

If an organization’s information assets are its crown jewels, the ISMS is the vault. It’s the people, systems, technology, process, and information security policies that all come together to protect sensitive data across the entire organization.

But an ISMS is more than just the hardware and software you use to keep information safe — it’s also a structured set of policies, processes, and governance principles that guide how your organization:

• Uses information
• Stores and retrieves data
• Assesses and treats risk
• Continuously improves data security

The purpose of an ISMS is to create a proactive, risk-based approach to protecting information, not just react to incidents after they occur. The process of building an ISMS helps you: 

• Identify key stakeholders and their information security requirements
• Set clear expectations and responsibilities around information security across the entire organization
• Identify threats to information assets
• Define and implement controls to mitigate vulnerabilities
• Monitor and measure performance of information security controls
• Continuously improve the ISMS 

Why the ISMS is central to ISO 27001

The ISMS isn’t just one part of ISO/IEC 27001, it’s the foundation of the standard. Without an ISMS, the framework has nothing to measure. Your ISMS is what an auditor evaluates to determine whether your organization meets the standard’s requirements.

The benefits of a compliant ISMS extend beyond ISO 27001 certification. A strong ISMS can:

• Build trust with customers and partners
• Improve operational efficiency
• Establish scalable security practices
• Strengthen operational resilience
• Reduce legal and regulatory risk
• Support alignment with other cybersecurity frameworks, such as SOC 2, NIST CSF, HIPAA, GDPR, etc.

In short: your ISMS is your organization’s playbook for protecting information, and ISO 27001 ensures that playbook is both comprehensive and effective.

What are the components of an ISMS?

An ISMS encompasses the four Ps: 

1. People: The employees, contractors, and leadership who interact with or oversee information assets.
2. Policies and processes: The documented rules and procedures for handling data securely.
3. Products and technologies: The technical tools and safeguards you use, such as encryption, access management, and monitoring systems.
4. Partners and third-party vendors: Any external parties who access or process your data.

In practice, an ISMS includes everything from HR processes like conducting background checks, to data encryption and secure development practices, to business continuity planning and vendor risk management. It includes anything and everything an organization does to identify and manage information security risks. 

The benefits of a compliant ISMS extend beyond ISO 27001 certification. It can also help you improve business efficiency, identify redundancies and lower costs, and establish scalable security practices. 

How to build an ISMS that meets ISO 27001 requirements

The ISO/IEC 27001:2022 standard defines the requirements for building and maintaining a compliant ISMS. Compared to earlier versions, the 2022 update simplified and modernized its security controls. Annex A now has 93 controls instead of 114, organized into four categories: Organizational, People, Physical, and Technological.

Here’s how to get started:

• Establish ISMS scope. Not every piece of information will fall under the scope of your ISMS. Under Clause 4.3, organizations must first define which information which assets, processes, or systems need to be protected and clearly document the boundaries. 
• Complete a risk assessment. Next, you’ll need to identify vulnerabilities for each information asset. A risk assessment will help you pinpoint specific threats, evaluate their likelihood and impact, and prioritize them.
• Create a risk treatment plan. Once risks are identified, you can decide what to do about them. Depending on your organization’s risk appetite, you can either accept, treat, avoid, or transfer the risk. Document these decisions and make sure they align with business goals.
• Design and implement security controls. Use ISO/IEC 27001 Annex A as your reference point for required controls. ISO/IEC 27002:2022 provides more detailed information on each control, including how to implement it in practice. Controls may include encryption, secure coding, physical access restrictions, or vendor security requirements.
• Perform regular internal audits. Once you’ve built your ISMS you need to verify that controls are worked as intended with regular internal audits. The results of these internal audits help you improve your ISMS and ensure it continues to meet your organization’s needs over time. 
• Define a process for continuous improvement. Management should review the ISMS regularly, using audit findings, monitoring data, and incident reports to identify improvements. ISO 27001 emphasizes continual improvement as a core requirement, ensuring your ISMS adapts to evolving risks.

If you're building out your ISMS and trying to achieve ISO 27001 certification, check out the video below for some invaluable tips.