The 8 security metrics that matter most

KPIs and metrics are indispensable for evaluating the effectiveness of enterprise cyber defenses. These crucial tools open insights into system vulnerabilities, threat patterns, and incident response efficiency. In a time of growing digital reliance, KPIs and metrics play an vital role in security decision-making, ensuring enterprise preparedness against ever-evolving cyber threats.

Regrettably, when it comes to deploying cybersecurity KPIs and metrics, it’s easy to get bogged down in a seemingly endless number of popular insights and indicators. Fortunately, just a handful stand out from the pack as essential for any cybersecurity strategy. Here are some of the best.

1. Mean time to detect

Mean time to detect (MTD) is a crucial metric that reflects an organization’s ability to quickly identify and address potential incidents, ultimately minimizing potential damage, says Mehdi Houdaigui, US cyber and transformation leader with enterprise consulting firm Deloitte.

A lower MTD indicates that your security organization quickly detects potential threats, reducing the window of opportunity for attackers to harm the organization, Houdaigui says. And with attack time frames shrinking rapidly, keeping MTD low will only become more important.

Still, Houdaigui says, MTD is only one of many metrics organizations will find useful. “It’s important for organizations to focus on what matters most and is strategic to their business,” he says.

2. Cyber resilience

Cyber resilience is the real measure of whether your security program is doing its job, says John Wheeler, CSO with professional services firm Cognizant.

“In the end it’s not about how many threats you block — which certainly matters — it’s about how quickly and effectively you’re able to recover when something gets through, which it eventually will,” he observes. “Resilience means your business keeps running, your customers stay confident, and a bad day doesn’t become a crisis.”

No system is entirely bulletproof. “Even the best defenses can be breached,” Wheeler says. What separates successful organizations from those spiraling downward is how quickly they respond and bounce back. “If you can recover in hours, it’s a headache. If it takes weeks, it’s a disaster,” he notes. “Resilience is the difference between a temporary issue and lasting damage — to your business, your reputation, and your customer trust.”

3. Network, system, and endpoint visibility

You can’t fix what you can’t see or don’t know. “If you don’t have visibility into the security of your endpoints, then you won’t be able to detect when one of your endpoints is compromised,” says Sandra McLeod, interim CISO at Zoom. “If you have full coverage of your production environments, but are missing security controls and visibility into your dev environments, then you may be lacking critical protection of your code and build processes.”

Visibility gaps create opportunities for attackers and blind spots for defenders.

One of the most common mistakes organizations make is failing to operationalize KPIs and metrics, McLeod observes, meaning they’re tracked, but not integrated into day-to-day business decisions. Another pitfall, she warns, is developing a false sense of security based solely on KPI performance. Just because the numbers look good doesn’t mean the organization is safe or fully secure. “It’s important to ask: What are these metrics not showing us?”

4. Goal question metric (GQM)

Richard Caralli, senior cybersecurity advisor at Axio, an SaaS-based cyber management software provider, suggests using the structured approach provided by goal question metric (GQM) to help tell your cyber value story.

“This metric can help organizations focus on cybersecurity process improvement by adopting time-honored methods from software process improvement,” he says. “GQM is particularly good for supporting governance needs, since it can help senior management and boards develop meaningful metrics that indicate program effectiveness.”

For example, a board may ask, “Are we remediating known vulnerabilities in a timely manner?” Some CISOs might answer that question by stating that a vulnerability management program, policy, and supporting processes are in place — but that doesn’t necessarily answer the question, Caralli says.

“In a GQM approach, one or more metrics can be established to answer this question and provide trend information that demonstrates competency over time,” he says.

5. Cost avoidance ratio

The effectiveness of a cybersecurity program can be effectively evaluated by using the cost avoidance ratio (CAR), a comparative measure of the costs associated with preventing, detecting, and responding to incidents versus the potential losses incurred from failing to do so, says Tim Lawless, master software architect and vulnerability remediation engineer at the Cybersecurity Manufacturing Innovation Institute.

Metrics that track an organization’s ability to detect, respond to, and recover from incidents can have a direct impact on the overall cost and disruption caused by such events, Lawless says. These expenses include containment costs, recovery efforts, and opportunity costs from operational downtime. “A higher CAR reflects a more effective cybersecurity posture, demonstrating that proactive investments in incident response capabilities are successfully minimizing potential damage and maximizing organizational resilience.”

6. Mean time between failures

In any business, but especially finance, reliability is absolutely foundational, says Jason Pack, chief revenue officer at loan firm Freedom Debt Relief, a debt relief services firm. That’s why mean time between failures (MTBF) has become such an essential metric for gauging cyber health.

“Customers and the market depend on constant access to services like online banking, payment processing, and trading platforms,” Pack observes. “A high MTBF shows that those systems are stable and trustworthy enough for people to count on them.”

MTBF provides a clear picture of how well an infrastructure is actually performing and how resilient it’s likely to be when faced with disruptions, whether simple tech issues or security threats, Pack says. “Keeping a close eye on MTBF can help you get ahead of operational risks, which is definitely a focus for regulators.”

With MTBF, it’s possible to anticipate potential problems, schedule maintenance more effectively, and ultimately maintain the deep customer trust sensitive industries are built on, Pack says. “At the end of the day, fewer system failures mean less expensive downtime, smoother operations for everyone, and stronger confidence that you can deliver reliably.”

7. Time to contain

Time to contain (TTC) is what truly determines resilience, claims Antony Marceles, a technology consultant and founder of software development firm Pumex. Detection alone isn’t enough, he notes. “If you can’t isolate and neutralize the threat swiftly, the cost of recovery can skyrocket.”

TTC not only reflects a security team’s responsiveness; it also shows how well the organization has integrated its security protocols, automation tools, and cloud infrastructure. “At our company, we’ve invested in automating containment actions for common threats and built cross-functional drills to test our response time, which has significantly shortened our TTC,” Marceles explains. “For any tech leader, optimizing these metrics can mean the difference between a minor disruption and a full-blown catastrophe.”

8. Reduction in successful phishing attempts

Reduction in successful phishing attempts (RISPA) directly addresses a very human element in security, says Gyan Chawdhary, vice president at IT cybersecurity firm Security Compass. He notes that even with the best technical controls, a well-crafted phishing email can trick an employee into giving away credentials or downloading malware.

“Tracking the success rate of these attacks, and showing a downward trend, indicates that your efforts in security awareness training, coupled with technical controls like email filtering and anti-phishing tools, are making a real difference in user behavior and your overall resilience,” he says.

The dangers of neglecting cybersecurity KPIs and metrics are akin to navigating a complex business without any financial reports, Chawdhary says.

“You’re operating in the dark, with no real understanding of your strengths, weaknesses, or the return on your security investments,” he explains. “This can lead to a misallocation of resources, a false sense of security, and ultimately, a higher probability of experiencing a significant security incident.”