Maturity Model Frameworks
BSIMM (Building Security In Maturity Model) BSIMM is descriptive model based on observed practices from real software security initiatives. BSIMM describes what organizations actually do, not what they should do. BSIMM organizes practices into twelve domains including governance, intelligence, secure software development lifecycle touchpoints, and deployment. Each practice has multiple levels. BSIMM enables peer comparison by showing how organization compares to similar organizations. Comparison identifies gaps and opportunities. BSIMM assessment involves interviews and evidence review across security and development teams. Assessment should be conducted by trained assessors. BSIMM is updated regularly based on new data from participating organizations. Regular updates keep model current. OWASP SAMM (Software Assurance Maturity Model) SAMM is prescriptive model defining what organizations should do to improve software security. SAMM provides roadmap for security program development. SAMM organizes practices into five business functions: Governance, Design, Implementation, Verification, and Operations. Each function has three security practices. Each practice has three maturity levels with specific activities and success metrics. Maturity levels provide clear progression path. SAMM enables organizations to set target maturity per practice based on risk. Not all practices require highest maturity. SAMM assessment is self-service with detailed questionnaires and scoring guidance. Self-assessment enables rapid iteration. CMMI (Capability Maturity Model Integration) CMMI defines five maturity levels: Initial, Managed, Defined, Quantitatively Managed, and Optimizing. Each level represents increasing process capability. CMMI was originally developed for software development but can be adapted to security functions. Adaptation requires mapping security processes to CMMI framework. CMMI emphasizes process definition, measurement, and continuous improvement. Process focus enables systematic capability building. CMMI certification requires formal assessment by authorized assessors. Certification provides external validation.Maturity Assessment
Evidence-Based Scoring Maturity assessment should be based on objective evidence including documentation, tool outputs, and metrics. Evidence prevents inflated self-assessment. Evidence should include process documentation, control implementation artifacts, and outcome metrics. Comprehensive evidence provides accurate assessment. Checkbox self-assessments without evidence provide false confidence. Evidence-based assessment is more accurate. Assessment should include interviews with practitioners to understand actual practices versus documented practices. Interviews reveal gaps between policy and practice. Engineering Outcomes Maturity assessment should include engineering outcomes in addition to process maturity. Outcomes demonstrate actual security improvement. Mean time to remediation (MTTR) for vulnerabilities measures responsiveness. Improving MTTR indicates maturing processes. Defect escape rate measures how many vulnerabilities reach production. Decreasing escape rate indicates improving prevention. Security incident frequency and impact measure overall security effectiveness. Decreasing incidents validate maturity improvements. Code coverage by security testing measures testing thoroughness. Increasing coverage indicates maturing testing practices. Scoring Calibration Scoring should be calibrated across assessors to ensure consistency. Calibration prevents scoring drift. Scoring rubrics should be detailed and specific. Detailed rubrics reduce subjectivity. Pilot assessments should be conducted to validate scoring approach. Pilots identify scoring issues.Capability Roadmapping
Target Maturity Definition Target maturity should be defined per practice based on business risk and regulatory requirements. Not all practices require highest maturity. High-risk areas including authentication, authorization, and data protection may require higher maturity. Risk-based targeting optimizes investment. Regulatory requirements may mandate minimum maturity levels. Compliance requirements should be incorporated into targets. Target maturity should be achievable within planning horizon (typically 1-3 years). Unrealistic targets demotivate teams. Initiative Sequencing Initiatives should be sequenced based on dependencies, risk reduction, and resource availability. Sequencing optimizes delivery. Foundation capabilities including governance and secure development lifecycle should be prioritized. Foundation enables other capabilities. Quick wins that deliver visible value should be included early. Quick wins build momentum and support. Dependencies between initiatives should be identified and respected. Dependency violations delay delivery. Ownership and Accountability Each initiative should have clear owner responsible for delivery. Ownership ensures accountability. Owners should have authority and resources to deliver. Ownership without authority fails. Success metrics should be defined for each initiative. Metrics enable progress tracking. Resource Planning Roadmap should include resource requirements including headcount, budget, and tools. Resource planning enables execution. Resource constraints should be identified early. Constraints may require roadmap adjustment. Hiring plans should align with roadmap. Hiring delays can derail roadmap.Progress Reporting
Quarterly Maturity Reviews Maturity should be reassessed quarterly to track progress. Quarterly cadence balances overhead with visibility. Maturity burndown charts show progress toward target maturity. Burndown provides visual progress tracking. Progress should be reported to executives and governance committees. Reporting maintains visibility and support. Budget Alignment Maturity roadmap should be tied to security budget. Budget should fund roadmap initiatives. Budget requests should reference maturity gaps and target maturity. Linkage justifies investments. Budget tracking should show progress on maturity initiatives. Tracking demonstrates value delivery. Trade-Off Communication Trade-offs between maturity investment and other priorities should be communicated clearly. Trade-offs enable informed decisions. Deferred maturity initiatives should be documented with risk implications. Documentation maintains visibility. Maturity targets may need adjustment based on resource constraints. Adjustment should be explicit and approved.Maturity Model Selection
Model Selection Criteria Model selection should consider organizational context, industry, and objectives. Different models suit different needs. BSIMM suits organizations wanting peer comparison and descriptive assessment. BSIMM shows what peers do. SAMM suits organizations wanting prescriptive roadmap and self-assessment. SAMM provides clear improvement path. CMMI suits organizations requiring formal certification or process focus. CMMI provides external validation. Multiple models can be used together. BSIMM for benchmarking and SAMM for roadmapping is common combination. Customization Models should be customized to organizational context. Generic models may not fit specific needs. Customization should maintain model structure while adapting practices. Structure provides consistency. Custom practices should be documented with rationale. Documentation enables future assessment.Conclusion
Security maturity models provide structured frameworks for assessing capabilities, setting targets, and building improvement roadmaps. Security engineers use maturity models to prioritize investments, track progress, and communicate program status. Success requires evidence-based assessment, risk-based target setting, and clear roadmaps with ownership and metrics. Organizations that invest in maturity model fundamentals build systematic capability improvement programs.References
- BSIMM (Building Security In Maturity Model)
- OWASP SAMM (Software Assurance Maturity Model)
- CMMI Institute
- NIST Cybersecurity Framework
- ISO/IEC 21827 Systems Security Engineering Capability Maturity Model