The primary purpose of information security metrics is to provide objective, quantifiable data that demonstrates the performance and effectiveness of the information security program. These metrics, often in the form of Key Performance Indicators (KPIs) and Key Risk Indicators (KRIs), allow management and stakeholders to assess whether security controls are working as intended, if program objectives are being met, and how well risk is being managed. This data-driven approach is crucial for justifying security investments, guiding strategic decisions, and facilitating continuous improvement of the program's posture.

A. Reducing spending is a potential outcome of an efficient program identified through metrics, but it is not the primary goal of establishing them.

B. Metrics are used to measure the success and impact of security initiatives, not merely to support their existence.

C. While metrics should align with the corporate risk culture (e.g., risk appetite), their fundamental purpose is to measure performance, not simply to reflect the culture.

1. ISACA

CISM Review Manual

15th Edition. Chapter 3

Section: "Information Security Program Management." The manual states that metrics are essential for "measuring

monitoring

and reporting on the effectiveness of information security controls and the overall information security program." It emphasizes that metrics provide assurance to stakeholders that security objectives are being achieved.

2. National Institute of Standards and Technology (NIST) Special Publication (SP) 800-55 Rev. 1

Performance Measurement Guide for Information Security. Section 2.1

"Purpose of an Information Security Performance Measurement Program

" explicitly states: "An information security performance measurement program helps an organization determine the effectiveness of its information security program

policies

and controls..."

3. ISACA

COBIT 2019 Framework: Introduction and Methodology. The framework's core principles revolve around governance and management objectives. The "Monitor

Evaluate and Assess" (MEA) domain

particularly MEA01

focuses on monitoring performance and conformance to ensure that enterprise and governance objectives are met

which is a direct measure of effectiveness.