ELI5: What is Ad Hoc vs. Recurring vs. Continuous?

Ad hoc is checking your bike after you crash. Recurring is checking it every Saturday. Continuous is having a sensor that beeps the moment something goes wrong. Companies check their security the same three ways.

Definition

Risk and security assessments can be performed on three schedules: ad hoc assessments are triggered by a specific event (e.g., a breach, new system deployment, or regulatory change); recurring assessments happen on a defined schedule (e.g., annual penetration tests or quarterly vulnerability scans); and continuous assessments use automated tooling to monitor the environment in real time. Each approach has trade-offs in cost, depth, and timeliness.

Key Details

  • Ad hoc: triggered by events such as mergers, incidents, or new threat intelligence — unplanned but necessary
  • Recurring: scheduled at regular intervals (annual, quarterly, monthly); required by many compliance frameworks (PCI DSS, HIPAA)
  • Continuous: automated monitoring tools (SIEM, vulnerability scanners) provide real-time visibility; closest to true situational awareness
  • Continuous assessments do not replace periodic deep assessments; they complement them
  • Exam tip: compliance frameworks often mandate at least recurring assessments; continuous is considered a maturity best practice

Connections