Continuity & Fallback (CNT)

What the layer describes

The CNT layer answers the question “What happens when the systems do not work?”. It describes how the public service (PublicService) continues during a disruption, including through manual alternatives. Technical recovery of the systems belongs to OPS.

Concepts and how they relate

A disruption scenario (DisruptionScenario) describes a situation that would interrupt the delivery of a public service. It affects a public service, a service access channel (ServiceChannel) or an exposed system, through the “affects” relationship (affects). An impact assessment (ImpactAssessment) evaluates the effects of the interruption.

A fallback procedure (FallbackProcedure) is the way the service is delivered during the disruption. Optionally, a public service, a channel or a procedure (Procedure) falls back to it, through the “falls back to” relationship (fallsBackTo). The fallback procedure optionally mitigates the scenario, through the “mitigates” relationship (mitigates). Optionally, a fallback resource (FallbackResource) that the procedure needs is assigned to it, through the “is assigned to” relationship (assignment).

After the disruption, a reconciliation procedure (ReconciliationProcedure) brings the work done through the fallback back into the normal records. Optionally, the fallback procedure triggers it, through the “triggers” relationship (triggering). Where needed, the steps of CNT procedures are drawn on their own detail sheets, with BPMN tools.

A restoration plan (RestorationPlan) sets the restoration priorities. The order between two elements is expressed through the “is restored after” relationship (restoresAfter). For example, a model shows that a public service is restored after the software system (SoftwareSystem) that supports it.

Element types

The layer has 8 element types, in these families: structure (1), behaviour (3), information (3), event (1). Each type's own fields are listed under its definition; the fields common to every element are described under the core concepts.

• DisruptionScenarioDisruption scenario · event family

  A situation that could interrupt delivery of a public service.

  Key attributes: kindlikelihoodimpact
• ImpactAssessmentImpact assessment · information family

  An assessment of the effects of a service disruption.

  Key attributes: subjectimpactTypesrestorationTiertechnicalRecovery
• FallbackProcedureFallback procedure · behaviour family

  An alternative way to deliver a service during disruption.

  Key attributes: activationCriteriaactivatedBydataCaptureMethodmaxDurationstaffingNeededreconciliationresources
• FallbackResourceFallback resource · structure family

  A resource required to operate an alternative service procedure.

  Key attributes: kindlocationquantity
• ReconciliationProcedureReconciliation procedure · behaviour family

  A procedure for bringing fallback activity back into normal records.

  Key attributes: deadlinevalidationStepsresponsibleRole
• CommunicationPlanCommunication plan · information family

  A plan for informing affected people and organisations during disruption.

  Key attributes: audienceschannelsmessageTemplates
• ContinuityExerciseContinuity exercise · behaviour family

  An activity that tests service continuity arrangements.

  Key attributes: heldOnscenarioTestedresultlessonsLearned
• RestorationPlanRestoration plan · information family

  A plan prioritising the restoration of public service delivery.

  Key attributes: disruption

In the “Family support benefit” example

Figure 4.10 (page 39) shows the CNT layer in the example. The disruption scenario “Portal unavailable” describes a prolonged outage of the channel “Public benefit portal”, from ORG, during which the counter stays open. The scenario affects the public service “Family support benefit”, from ORG.

The service then falls back to the fallback procedure “Assisted paper intake”. Counter staff take paper applications and enter them once the software system “Benefits case platform”, from APP, is back. The architecture decision (ArchitectureDecision) “ADR 1: assisted intake”, from X, is associated with the procedure, through the “is associated with” relationship (association).

The reconciliation procedure “Reconcile assisted cases” enters the numbered forms and looks for applications submitted twice, both on paper and online. The fallback procedure names it in a field, which is why the figure does not link them.