By Blacklock Security Limited 
Penetration Testing as a Service (PTaaS) has redefined how modern organizations assess and manage security risks. Unlike traditional pen tests that offer a one-time snapshot, PTaaS delivers continuous, scalable, and integrated testing tailored to today’s agile development environments. But with this shift in model comes a new challenge how do you measure its effectiveness?
To truly extract value from a PTaaS engagement, it’s essential to track the right performance metrics. In this blog, we’ll break down the key technical and operational indicators you should monitor during a PTaaS deployment and explain why they matter for your engineering, DevSecOps, and compliance teams.
1. Time to Vulnerability Discovery (TTV)
One of the main advantages of PTaaS is speed. Traditional pen tests often take weeks to schedule, execute, and report. In contrast, PTaaS platforms integrate directly with CI/CD pipelines or version control systems, offering near-real-time feedback on new vulnerabilities.
Time to Vulnerability Discovery (TTV) measures how quickly the platform detects a new exploitable issue after code is pushed or infrastructure is deployed.
Why It Matters:
- Shorter TTV means faster feedback loops for development teams.
- Reduces the window of exposure in production environments.
- Demonstrates the responsiveness of your PTaaS provider.
To improve TTV, look for automated scanning hooks that trigger on commit, merge, or deployment events. Make sure the platform supports both on-demand and scheduled tests for flexible coverage.
2. Mean Time to Remediate (MTTR)
MTTR is the average time it takes from vulnerability discovery to verified remediation. PTaaS platforms streamline remediation by providing in-context guidance, ticketing system integration, and real-time retesting.
This metric reflects how efficiently your security and engineering teams work together to close the loop.
Key Drivers for Lower MTTR:
- Quality of remediation advice provided.
- Developer access to actionable insights and POCs.
- Integration with your JIRA, Slack, or ticketing system for faster triage.
- Availability of automated retesting after code updates.
Tracking MTTR highlights bottlenecks in your patching and prioritization workflows. It also supports SLAs and internal KPIs tied to risk mitigation timelines.
3. Exploitability Ratio
Not all vulnerabilities are created equal. The Exploitability Ratio compares the number of exploitable (e.g., critical/high-severity) findings to the total vulnerabilities identified.
A high exploitability ratio indicates that attackers could realistically compromise your system using publicly known techniques or exploits.
PTaaS Context:
Platforms like Blacklock PTaaS categorize vulnerabilities by severity and exploitability, often enriched with CVSS scores, CWE IDs, and custom business impact ratings. This ratio helps teams focus on what matters most vulnerabilities that actually pose real-world risks.
4. Vulnerability Recurrence Rate
Do the same vulnerabilities keep coming back after being fixed?
The Vulnerability Recurrence Rate tracks how often previously resolved issues reappear in later scans. This is critical for measuring the long-term effectiveness of your development and DevSecOps processes.
Use Cases:
- Identifying gaps in secure coding practices.
- Verifying if regression tests for security are in place.
- Flagging code ownership or documentation issues within large teams.
If you’re seeing high recurrence, it may be time to revisit static analysis policies, coding guidelines, or team-wide security training initiatives.
5. Asset Coverage Ratio
Asset coverage is often overlooked, but it’s one of the most crucial metrics in a PTaaS deployment.
The Asset Coverage Ratio is the percentage of your attack surface web apps, APIs, infrastructure endpoints, and cloud resources that is regularly tested by the PTaaS platform.
Why It Matters:
- Unscanned assets are unmonitored attack vectors.
- High coverage reduces blind spots in your security program.
- Helps satisfy regulatory frameworks (e.g., ISO 27001, SOC 2, PCI DSS) that mandate comprehensive testing.
The best penetration testing as a service platforms offer dynamic asset discovery to ensure that your ever-expanding digital surface is always within scope.
6. Time to Report Generation
Security teams often need to generate detailed reports for internal stakeholders, auditors, or customers. The Time to Report Generation metric measures how quickly these reports can be produced and shared after test completion.
Modern PTaaS tools offer:
- One-click PDF and HTML report generation.
- Custom branding and formatting for client-facing reports.
- Live dashboards for real-time sharing of test results.
Reducing report turnaround times enhances agility, particularly during audits, incident response, or client due diligence processes.
7. Number of Critical Issues Missed by SAST/DAST
PTaaS doesn’t replace SAST (Static Application Security Testing) or DAST (Dynamic Application Security Testing) it complements them. A valuable metric to track is how many critical issues were discovered via PTaaS that were missed by traditional scanning tools.
This metric justifies the need for manual testing, business logic analysis, and red teaming components embedded in PTaaS.
If you find significant gaps, you might want to extend your coverage with Static Application Security Testing Services, which bring deeper code-level insights that traditional black-box scanners may overlook.
8. Mean Time to Validate Fix (MTTVF)
Once your developers deploy a fix, how long does it take to confirm its effectiveness?
The Mean Time to Validate Fix (MTTVF) reflects how quickly the PTaaS provider or platform can verify that a patched vulnerability has indeed been resolved. Some platforms offer push-button retesting or automated validation that shortens this cycle dramatically.
MTTVF Optimization Tactics:
- CI-based auto-retesting on pull request merge.
- Slack notifications for test completion alerts.
- In-dashboard status indicators for verified patches.
Lowering MTTVF minimizes operational lag and supports faster compliance cycles.
9. SLA Adherence Rate
If you’re using a managed PTaaS solution, check if your provider meets their committed SLAs for:
- Discovery
- Reporting
- Retesting
- Support response time
Tracking the SLA Adherence Rate ensures accountability and allows you to benchmark vendors for performance reviews or renewals.
If you operate in a high-compliance industry, SLA metrics should be integrated into vendor risk management dashboards and procurement policies.
10. Security Debt Over Time
Finally, one of the most strategic metrics to track is your Security Debt the cumulative backlog of unresolved, known vulnerabilities across systems.
Monitoring how this debt increases or decreases over time is a direct indicator of your organization’s security health. Some PTaaS dashboards offer time-based charts that track open vulns, severity distribution, and fix rates month over month.
Security debt should trend downward. If not, investigate:
- Resource constraints on remediation teams.
- Inadequate prioritization models.
- Lack of C-suite support for security engineering.
Final Thoughts
PTaaS isn’t just a security service it’s a measurement engine. Tracking metrics like TTV, MTTR, Exploitability Ratio, and Coverage Rate transforms penetration testing from a reactive task to a proactive strategy.
By leveraging intelligent PTaaS platforms like Blacklock PTaaS, you empower your teams to make data-driven decisions, improve development cycles, and stay ahead of evolving threats especially in dynamic regions like Australia and New Zealand, where fast-paced tech adoption demands constant vigilance.
