When to Threat Model
Threat modeling is most effective when it is done early enough to influence design and often enough to stay accurate.
This guide explains when you should create, update, or revisit a threat model so it remains a practical tool rather than a one-time exercise.
Threat model early
Create a threat model as early as possible in the design process.
Threat modeling is most valuable when it can influence:
- Architecture decisions
- Technology choices
- Security controls
- Integration design
You do not need a complete design to start. A high-level model is often enough to surface important risks early.
Tip
Start with what you know. Threat models can evolve as the system becomes more defined.
Threat model when something changes
Threat models should be updated whenever meaningful change occurs.
Common triggers include:
- Adding a new feature or capability
- Introducing a new integration or third-party service
- Changing how sensitive data is processed or stored
- Modifying authentication or authorization behavior
- Crossing new trust boundaries
If the system changes, the threat model should change with it.
Threat model before implementation
Threat modeling is most effective before code is written.
Doing this early helps teams:
- Identify design risks before they are expensive to fix
- Avoid rework caused by late security findings
- Make informed trade-offs between functionality and risk
Threat modeling should inform implementation, not react to it.
Threat model after security events
Threat models are also valuable after something goes wrong.
You may want to revisit a threat model after:
- A security incident or near miss
- A penetration test or assessment
- Discovery of a new class of vulnerability
- Changes in regulatory or compliance requirements
In these cases, the threat model helps validate whether risks were understood and whether controls are sufficient.
Threat modeling is an ongoing practice
Threat models are living artifacts, not static documentation.
A healthy threat modeling practice involves:
- Revisiting models as systems evolve
- Refining attributes and mitigations over time
- Using threat models to support design reviews and planning
Devici is designed to support continuous threat modeling as part of normal development workflows.
What’s next
Now that you know when to threat model, you’re ready to build your first one.
Threat modeling is most effective when it becomes part of how systems are designed, built, and maintained.