Maintaining and Evolving Threat Models
Threat models are most valuable when they evolve alongside the systems they describe.
In Devici, threat models are living artifacts. As systems change, threat models should be updated to reflect new components, data flows, trust assumptions, and decisions.
This section explains how to keep threat models accurate, relevant, and useful over time without turning maintenance into overhead.
Treat threat models as living artifacts
Systems rarely stay static.
Threat models should be updated when:
- New features or services are introduced
- Existing components change behavior
- Data flows are added or removed
- Trust assumptions shift
- New integrations are introduced
Keeping models current ensures identified threats remain meaningful and actionable.
Make small updates frequently
Small, incremental updates are easier to manage than large revisions.
Instead of waiting for major changes:
- Update the model as part of feature work
- Adjust attributes when behavior changes
- Add or remove elements as the system evolves
Frequent updates reduce the risk of models becoming outdated or ignored.
Use threats as feedback
Identified threats provide insight into the model itself.
Use threats to ask:
- Are attributes applied accurately?
- Are trust boundaries placed correctly?
- Are important data flows missing?
- Are threats appearing that no longer apply?
Unexpected threats often indicate that assumptions need refinement rather than that something is “wrong.”
Revisit actions as assumptions change
Actions are based on context and assumptions at a point in time.
As systems evolve:
- Mitigations may no longer be sufficient
- Accepted exposure may need reevaluation
- Deferred actions may become relevant
Periodically reviewing actions helps ensure they remain aligned with the current system design.
Use reviews to recalibrate
Threat model reviews aren’t only for new designs.
Reviews are useful when:
- Major architectural changes occur
- Ownership of components changes
- Teams or responsibilities shift
- Security posture expectations evolve
Even lightweight reviews help validate that the model still reflects reality.
Align updates with development workflows
Threat model maintenance should fit naturally into existing workflows.
Common approaches include:
- Updating models during feature development
- Reviewing threats during design or architecture discussions
- Revisiting actions during security reviews or milestones
Devici supports this by keeping models, threats, and actions tightly connected.
Know when to simplify
Over time, threat models can accumulate unnecessary detail.
Periodically consider:
- Removing obsolete components
- Consolidating elements where detail no longer adds value
- Marking parts of the model out of scope when appropriate
A simpler, accurate model is more valuable than a detailed but outdated one.
Measuring long-term value
Well-maintained threat models provide ongoing value by:
- Preserving institutional knowledge
- Making security considerations visible
- Supporting onboarding and handoffs
- Enabling consistent decision-making
Threat modeling becomes part of how teams understand and evolve their systems.
What’s next
You’ve now completed the Get Started Tutorial.
From here, you can:
- Explore Guides for specific features and workflows
- Review Release Notes to stay up to date
- Apply Devici to additional systems and teams
Threat modeling is not a one-time task — it’s a continuous practice that grows with your systems.