Scenario Testing and Exercises
How scenario testing turns a disruption story into decisions, rehearsals and changes, so an important service can be kept running or restored within its tolerance.
Line 19: Scenario testing and exercises
Severe but plausible scenarios, exercises that rehearse them, and the lessons that change a plan instead of sitting in a report.
The line guide
Working guides on this line
Designing Severe but Plausible Scenarios
How to design a scenario that is severe enough to breach tolerance yet plausible enough to be believed, using the service, its dependencies and its history as the test.
Exercises for Incident Teams
How incident team exercises test roles, handovers, decision logs and coordination under pressure, including when the team itself is tired or incomplete.
Exercises for the Board
How board exercises test strategic judgement, risk appetite, external communication and oversight, rather than technical detail or operational procedure.
Learning from Exercises
How learning from exercises becomes real change, through honest debriefs, owned actions, retesting and sharing lessons without blame or softening findings.
Live Exercises Without Harming Customers
How live exercises test real systems and people safely, using ring fencing, stop criteria, rollback plans and customer impact checks before and during the test.
Scenario Libraries and Maintenance
How a scenario library stays useful, with versioning, retirement, service links and reviews triggered by change, so old stories do not rehearse old services.
Scenario Testing for Cyber Outages
How a cyber outage scenario tests coping while systems are unavailable, including manual workarounds, customer communication and decisions about what waits.
Scenario Testing for Cyber Recovery
How cyber recovery scenarios test rebuilding cleanly, verifying integrity, and returning to normal in stages, rather than simply restarting affected systems.
Scenario Testing for Data Loss
How data loss scenarios test integrity, reconstruction and trust, when records are missing, corrupted or cannot be relied on after a disruption to a service.
Scenario Testing for Supplier Failure
How supplier failure scenarios test substitutes, exit routes and customer harm when a provider a service depends on stops, degrades or cannot be reached.
Scenarios for Emerging Risks
How to build provisional scenarios for risks that are new, uncertain or only partly understood, using weak signals, plausible chains and regular revision.
Tabletop Exercises That Work
How a tabletop exercise can test judgement and coordination through discussion, injects and disagreement, without touching live systems or live customers.