ART-2025 • Module 6 • Outcome of Safety Management System
Hazard → Risk → SCARS → Acceptance → Safety Case
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Outcome of the Safety Management System Overview

  Safety Management System (SMS) Definitions
  • SMS: formal, documented way to manage safety through policy, assurance, and promotion, not just reacting after incidents.
  • Safety: risk is reduced and controlled to an acceptable level for operations at LGBI / AAI.
  • Hazard: any condition or object with the potential to lead to an incident or accident (examples: weather, FOD, comm failure, human overload).
  • Safety Risk: the predicted probability and the predicted severity of a hazard’s consequences.
Why does this matter in ATC?
  • Controllers are continuously doing risk assessment in real time, not only passing clearances.
  • Good situational awareness means you catch a developing threat early, so recovery is simple and quiet instead of headline-worthy.
  • AAI needs evidence that risk is understood, mitigated, and owned by the correct authority level (APD/HOD, GM, ED).

Risk Fundamentals Probability × Severity

  Probability levels (5 → 1)
  • 5 — Frequent: expected to happen often
  • 4 — Occasional: will happen sometimes
  • 3 — Remote: could happen, not routine
  • 2 — Improbable: very unlikely
  • 1 — Extremely Improbable: almost inconceivable
  Severity levels (A → E)
  • A — Catastrophic: hull loss, fatality, major facility damage
  • B — Hazardous: serious injury / near catastrophe / major ATC breakdown
  • C — Major: significant incident, loss of separation
  • D — Minor: small effect on safety margins
  • E — Negligible: minimal safety impact
Putting them together

Safety Risk = How likely is it? (probability) × How bad if it happens? (severity). We don't just say “risky” — we show where it sits in a matrix.

Interactive Risk Matrix Class I / II / III / IV

  Click to explore Interactive
Probability ↓ / Severity → A B C D E
5 — Frequent5A5B5C5D5E
4 — Occasional4A4B4C4D4E
3 — Remote3A3B3C3D3E
2 — Improbable2A2B2C2D2E
1 — Ext. Improbable1A1B1C1D1E
Selection

Click a Severity header (A–E), then a Probability row (5–1).

Who can accept what?
  • Class I (e.g. 5A,4A,3A): Unacceptable
  • Class II (ALARP): Accepted at ED level after mitigation
  • Class III: Tolerable — Accepted by GM
  • Class IV: Acceptable — Accepted by APD / HOD

Risk Assessment Lifecycle When we assess

  When do we apply safety assessment? Lifecycle
Existing systems:
  • Triggered when a safety concern is perceived
  • Use both proactive and reactive data
New systems / changes:
  • Start at concept / design
  • Continue through execution
  • Review again before commissioning
Stages:
  • I: Concept / Design
  • II: Execution (work in progress)
  • III: Commissioning (pre-ops)

Small projects may merge I+II, but Stage III (commissioning) is always its own safety check.

  8-Step Method Procedure
  1. Describe the system & environment.
  2. Apply SCARS early (concept/design).
  3. Identify hazards (HAZID).
  4. Estimate probability & severity.
  5. Evaluate risk with existing controls.
  6. Plan mitigations to reduce risk.
  7. Re-evaluate residual risk after mitigation.
  8. Get formal acceptance at the correct authority level.

“Describe the system” means: purpose, scope, boundaries, procedures, operating environment, who uses it, any transition steps, and interfaces.

HAZID & SCARS Identify change impact

  HAZID (Hazard Identification) Workshop
  • Guided workshop / brain-storm with ATC ops, CNS/Tech, Safety, HR, etc.
  • List hazards, possible consequences, and existing controls.
  • Classify initial risk for each hazard.
  • Record in a HAZLOG (hazard log).

HAZID is where you capture “what can go wrong” before it actually goes wrong in live ops.

  SCARS (Safety Case And Risk Summary) Step 1 / 2 / 3

SCARS is applied very early for any change or new system. It does 3 big things:

  1. Size of Change (Small / Medium / Large)
    – How widely does this touch operations, tech, procedures, training, stakeholders?
  2. Safety Outcome from Preliminary Hazard Analysis (Minimal / Reasonable / Substantial)
    – How serious are the hazards overall?
  3. Overall Safety Magnitude (Minor / Moderate / Major)
    – This drives what documentation and approvals we must produce.

SCARS — Overall Safety Magnitude Interactive

  Determine Minor / Moderate / Major Interactive
Size of the Change Substantial Reasonable Minimal
Large Major Major Moderate
Medium Major Moderate Minor
Small Moderate Minor Minor

Click one Size row (Small / Medium / Large) and one Outcome header (Minimal / Reasonable / Substantial). The table will highlight the resulting Magnitude.

Your Selection
Rule of thumb: – Large + Minimal → Moderate – Medium + Minimal → Minor – Small + Substantial → Moderate

Reporting Requirements Documentation & Acceptance

  Minor / Moderate / Major What you must produce
Minor
  • Fill SCARS including a Safety Statement: explain why risk is already low.
  • Show minimal or no new safety impact.
  • Get signatures/acceptance at the correct local authority level.
Moderate
  • Run a HAZID workshop and open a HAZLOG.
  • Attach HAZID output + mitigations to SCARS.
  • Document how risk is driven down to ALARP (“As Low As Reasonably Practicable”).
Major
  • Prepare a Safety Plan (scope, roles, milestones, training, responsibilities).
  • Carry out HAZID, maintain the HAZLOG, and develop mitigations.
  • Prepare a Safety Case and get it reviewed / endorsed / approved.
  • Post-Implementation Review (PIR): confirm in real ops that the mitigations work; update the Safety Case.

The Safety Case is formal proof that “we can safely do this new thing at this airport / unit.”

Quick Quiz Knowledge Check

  Answer & learn Self-check
Loading quiz…
Remember
  • Risk = Probability × Severity.
  • Class II (ALARP) needs ED-level acceptance.
  • “Major” changes need Safety Plan + Safety Case + PIR.
  • SCARS starts at the concept stage, not at the end.