What it means
Impact translates a technical failure into consequences for people and the organization. A deleted table matters because appointments disappear, invoices become wrong, or an essential service stops. Start with the activity that depends on the asset, then describe the harm if confidentiality, integrity, or availability fails.
Consequences may grow with time and spread through dependencies. An hour of disruption during a quiet period may differ from an hour during payroll or emergency operations. Include safety, privacy, financial loss, service delivery, and recovery effort where relevant. Keep the consequence estimate separate from how likely the event is to occur.
The idea at a glance / Risk
Describe the work that cannot get done.
An unavailable dispatch planner matters because repair crews need current assignments. A short exercise and a longer-outage estimate carry different evidence.
Fictional water utility, 25 September 2026. DispatchPlanner supplies repair assignments. The owner reviewed a 30-minute outage exercise and a separate eight-hour scenario.
READ THE PICTURE
Read the evidence and limits
The 30-minute exercise dispatched four urgent jobs and held eleven planned jobs. The eight-hour outlook predicts delays as paper falls behind. It is an owner estimate, not a test result or probability.
Keep in mindThe eight-hour consequences are estimates, not observed drill results. This figure measures neither outage probability nor injuries, service-wide effects, or a financial total.
Read the complete example
- Read the evidence and limits. The 30-minute exercise dispatched four urgent jobs and held eleven planned jobs. The eight-hour outlook predicts delays as paper falls behind. It is an owner estimate, not a test result or probability. DispatchPlanner’s loss of availability is the assumed event for this impact assessment, not a prediction that it will occur. On 25 September 2026, the fictional utility runs a controlled 30-minute dispatch exercise with four urgent jobs and eleven planned jobs, using a paper list and radio contact while the planner is unavailable. Staff dispatch all four urgent jobs and hold the eleven planned jobs until the exercise ends. No actual repair completion or customer-service outcome is measured. The dispatch owner confirms those exercise results. A separate eight-hour scenario assumes new assignments and changes continue through a working day. The owner estimates that the paper fallback cannot keep a full day of changing assignments current, which could delay field repairs and add reconciliation work after restoration. That is an owner-supported forecast, not an eight-hour test result or an automatic extrapolation of the eleven-job queue. The two durations are alternative scenarios, not sequential chapters of one outage. They demonstrate that a fallback can limit some consequences without sustaining every required task. Crew travel, customer service effects, safety harm, recovery effort, and financial costs would need additional evidence and assessment; no injury or currency total is asserted here. Keep these consequence questions separate from how likely an outage is.
The eight-hour consequences are estimates, not observed drill results. This figure measures neither outage probability nor injuries, service-wide effects, or a financial total.
Diagram references: NIST SP 800-30 Rev. 1 - risk factors, assumptions and assessment limits
AN ILLUSTRATIVE SCENARIO
A water utility maintenance system
A utility uses a scheduling application to coordinate field repairs. Losing access to the application would delay planned work; corrupting the location of an urgent repair could misdirect a crew. Operations staff explain that a paper dispatch process can cover a short outage, but it cannot sustain a full day of changing assignments. The security team documents those distinct consequences and the limits of the fallback. It avoids assigning an arbitrary financial total without operational evidence.
Put it to work
- Ask the service owner who depends on the asset, what decisions it supports, and what happens when its information becomes wrong or unavailable.
- Describe plausible consequences at meaningful durations or scales, including dependencies and existing manual workarounds.
- Use an agreed impact scale and record its rationale, assumptions, and the owner who can validate the business consequences.
How to check your work
Check the assessment with the people running the service. They should recognize the stated consequences, confirm the fallback's limits, and identify the point where a disruption becomes materially worse.
Connect the ideas
- Likelihood
How plausible it is that a threat will cause a loss in this environment, given exposure and evidence.
- Risk
The potential for harm, assessed using what could happen, how likely it is, its impact, and what remains uncertain.
- Asset
Anything whose disclosure, alteration, destruction, or downtime would harm a person or organization.
- CIA triad
A shorthand for naming whether a loss is disclosure, unauthorized change, or downtime.