Building secure software isn’t just about implementing controls – it’s about measuring how effective those controls are. So, let’s talk about security metrics and KPIs.

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01 – What are security metrics and KPIs?

Security metrics are quantifiable measures that assess how well your organisation is protecting its systems and data.

Think of metrics as a way to track activities (e.g. vulnerabilities discovered), while KPIs focus on outcomes tied to strategic goals (e.g. mean time to detect incidents).

Together, they provide actionable insights to strengthen your security posture.

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02 – Why measure security effectiveness?

Metrics remove the guesswork from security by offering a clear, data–driven picture of performance.

They help optimise resources by identifying high–impact risks, and improve decision–making with actionable insights.

They’re useful for communicating progress to stakeholders, justifying budgets and compliance efforts, and driving continuous improvement by highlighting weak areas and tracking trends.

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03 – Which metrics should you track?

There are a vast number of possible metrics you could track. Here’s a summary of key areas to focus on.

• Vulnerability management: How many known vulnerabilities are open, and how quickly are they being resolved?
• Security testing coverage: Measure the percentage of your applications, services, or infrastructure scanned using SAST, DAST, IAST, and SCA tools.
• Incident response times: Tracking metrics like mean time to detect (MTTD), mean time to acknowledge (MTTA), mean time to contain (MTTC) and mean time to resolve (MTTR). Faster times indicate stronger processes.
• Preparedness: Are your systems fully patched? Are your teams completing their security awareness training?
• Access management: Evaluate the number of admin accounts, privilege escalations, failed login attempts, authentication success rates, and role reviews to ensure least privilege adherence.
• Security incidents: Monitor incident volume, severity, and root causes to identify recurring issues.
• Compliance adherence: Track SOC 2, ISO 27001, and NIST compliance (and/or others as relevant to your organisation), alongside policy violations, audit findings and remediations.
• Cost per incident: Quantify the financial impact of breaches to guide resource allocation.

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Measuring security in your SDLC isn’t just a best practice – it’s a way to gain a competitive advantage.

By understanding what’s working (and what isn’t), you’ll be better positioned to build a more resilient, proactive, and data–driven security strategy.