Primary definition
Any system function, the compromise of which would degrade the effectiveness of that system in achieving the core mission for which it was designed. Source: CNSSD No. 505
Also known asmission-critical function · mission critical function · MCF · mission-essential functionality · mission essential function · MEF · core mission function · critical mission function
1 sources cited4 related termsReviewed Aug 9, 2026
— Committee on National Security Systems Glossary CNSSI 4009-2015View source
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CNSSGC
Any system function, the compromise of which would degrade the effectiveness of that system in achieving the core mission for which it was designed. Source: CNSSD No. 505
Committee on National Security Systems Glossary CNSSI 4009-2015 · 2024
Cite this term
Permanent URL · stable across revisions
Election Security Glossary. (2026). Mission Critical Functionality. In Election Security Glossary. Retrieved August 15, 2026, from https://electionsecurityglossary.com/glossary/mission-critical-functionality
Sources
1 cited · last checked Aug 9, 2026
01
Committee on National Security Systems Glossary CNSSI 4009-2015
Committee on National Security Systems Glossary CNSSI 4009-2015
Single-source
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