Identifying Existing Controls

Before recommending new security measures, catalog existing controls in your system. This inventory prevents redundant recommendations and identifies gaps in current defenses. Review your diagram and attack scenarios, noting where controls already exist and evaluating their effectiveness.

Technical controls might include firewalls, encryption, authentication mechanisms, and logging systems. Document not just their presence but their configuration and scope. A firewall that allows all outbound traffic provides different protection than one with strict egress filtering. Encryption at rest doesn't help if data is transmitted in clear text. Understanding control specifics reveals whether they adequately address identified threats.

Process controls encompass policies, procedures, and practices that enhance security. These might include code review processes, change management procedures, access approval workflows, and incident response plans. While less visible than technical controls, process controls often provide critical defense layers. However, their effectiveness depends on consistent implementation and regular validation.

Identify control gaps where threats lack corresponding defenses. These gaps represent your highest priorities for security improvements. Sometimes gaps exist because controls were never implemented; other times, evolving threats or system changes created new vulnerabilities. Your threat model highlights these gaps systematically rather than relying on ad-hoc discovery.