CSP-11 CSP-11 D2.04 · Domain 2 · Program Management · 25%
Investigation Tools: MORT/Barrier vs 5-Why
A serious machine injury has already produced a neat 5-Why chain ending at 'operator error,' but the guard was removed, the interlock was defeated, and supervision knew bypasses were common. Stop extending one chain. Map the barriers, then use MORT-style logic to trace why those control failures were allowed.
Updated . Independent CSP-11 practice. Not BCSP-endorsed. No pass guarantee.
Decision rule
Investigation methods must fit the system complexity.
5-Why on a SIS failure will miss independence.
In 20 seconds
- Investigation methods must fit the system complexity.
- Match the investigation tool to the question.
- 5-Why is for a single chain, not a multi-barrier event.
- Barrier analysis marks missing / failed / bypassed / effective.
How to apply Investigation Tools: MORT/Barrier vs 5-Why
THEORY: Barrier analysis, change analysis, fault tree as needed. Interview without blame. CALC: None. FIELD: Process release written as ‘operator error’ in two lines. Rebuild with layers. ASSESS: One method for every event is the trap.
Worked case
Wrong first move: Two-line 5-Why. Correct move: Pick the method that can see the system.
Why the rule holds
Related: 20, 105.
Same rule, different setting
A hydrocarbon release occurs from a pump after a high-vibration alarm was bypassed, the automatic trip was inhibited, and inspection findings remained open. A single 5-Why chain lands on 'production pressure.' Map each failed or missing barrier and trace the management conditions behind it.
A suspended precast panel strikes a worker after an uncertified lifting point fails and the exclusion zone is not maintained. The first interview blames the rigger. Preserve the evidence, map the prevention and mitigation barriers, and investigate why the lift plan, equipment control, and work-zone controls broke down.
Picture / model
Event sequence → intended barriers → status of each barrier (present/effective, degraded, bypassed, absent) → causal factors → management-system contributors → corrective actions → effectiveness verification. Use 5-Why for a bounded chain, not as proof that one chain explains a multi-barrier event.
Exam traps
Original SafePath contrasts for Investigation Tools: MORT/Barrier vs 5-Why. These are study traps, not recalled BCSP items.
| Trap | Correct read |
|---|---|
| 5-Why | Single causal chain drill |
| Barrier analysis | Missing vs failed vs bypassed controls |
| MORT-style | Control omission plus management-system omission |
| FTA | Deductive TOP-event combinations |
| FMEA | Design-stage failure modes — not reconstruction |
Field move
Field decision: 5-Why on that single chain after the facts are clear.
Scenarios
Scenario 1 · Fundamental · CSP-11 D2.04
A simple slip with one obvious missing barrier and no other actors. Best first tool?
Best action: 5-Why on that single chain after the facts are clear.
Why: Evaluate the best response. A fault tree works down from a top event. An event tree works forward from an initiator. AND needs every input. OR needs any input. Do not assume independence when a power feed or a common tap is shared. This item does not quote a fault-tree handbook. A simple slip with…
Scenario 2 · Applied Scenario · CSP-11 D2.04
An investigation finds a barrier was installed but bypassed during the event. How should the team classify and address it?
Best action: Failed or bypassed — restore independence, do not only rewrite the SOP.
Why: Evaluate the best response. A fault tree works down from a top event. An event tree works forward from an initiator. AND needs every input. OR needs any input. Do not assume independence when a power feed or a common tap is shared. This item does not quote a fault-tree handbook. An investigation fi…
Scenario 3 · Advanced Engineering · CSP-11 D2.04
Last sentence: five-why blamed hurry-up culture. Three engineered safeguards were never specified. Best move?
Best action: Treat culture as a contributor; specify the missing engineered barriers as primary CAPA.
Why: Evaluate the best response. A fault tree works down from a top event. An event tree works forward from an initiator. AND needs every input. OR needs any input. Do not assume independence when a power feed or a common tap is shared. This item does not quote a fault-tree handbook. Last sentence: five…
If the stem says this
| Stem signal | Best direction |
|---|---|
| five-why already blamed the operator | escalate to barrier/MORT |
| stem asks how combinations produced a TOP event | FTA, not 5-Why |
| design-stage failure modes | FMEA |
| several safeguards were supposed to protect | map barriers first |
| CAPA is retraining only | specify or restore a higher barrier |
| two answers work | higher hierarchy / system / design |
Check before you leave
- ✓ Match the investigation tool to the question.
- ✓ 5-Why is for a single chain, not a multi-barrier event.
- ✓ Barrier analysis marks missing / failed / bypassed / effective.
- ✓ MORT-style asks management-system omissions, not only the last act.
- ✓ CAPA must restore or add a higher barrier.
- ✓ FMEA is not an incident reconstruction.
Blueprint mapping
Investigation Tools: MORT/Barrier vs 5-Why is the SafePath study class for CSP-11 D2.04 inside CSP-11 Domain 2, Program Management (25%). A high-weight management domain focused on measuring performance, investigating incidents, managing change, building systems, leading people, controlling records and resources, and interpreting data.
SafePath uses the publicly posted CSP-11 outline as a study map. It does not reproduce official exam content, and it is not affiliated with or endorsed by BCSP or Pearson VUE.
Practice / flashcards / formulas
More classes in Program Management
Nearby lessons mapped to the same CSP-11 domain.
CSP-11 D2.04
Other classes on this task
Guides that use Investigation Tools: MORT/Barrier vs 5-Why
- Oil and gas safety study guideProcess safety, change, and investigations
- CSP application and exam guideEligibility, scheduling, and exam method
- CSP-11 exam prep guideDomain weights, sample items, and a study sequence
- CSP-11 blueprint and weightsSeven published domains and the class map
- Seven-domain study directoryScope, tasks, and links into each lesson
Investigation Tools: MORT/Barrier vs 5-Why study questions
- What decision does the Investigation Tools: MORT/Barrier vs 5-Why class train?
- Investigation methods must fit the system complexity. This is independent SafePath CSP practice for CSP-11 D2.04. It is not an official BCSP item and it is not a pass guarantee.
- What exam trap shows up in Investigation Tools: MORT/Barrier vs 5-Why?
- A common miss treats this as sufficient: 5-Why The stronger read is: Single causal chain drill
- How does Investigation Tools: MORT/Barrier vs 5-Why map to the CSP-11 blueprint?
- SafePath maps this class to CSP-11 D2.04 in Domain 2, Program Management (25% of the published blueprint). Use the public outline for study planning. SafePath is not affiliated with or endorsed by BCSP.
Verify
Verify: Confirm current certification requirements with BCSP and technical requirements with the cited authoritative standard.