Root Cause Tutorial

2013

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More on Hazard Identification Techniques

1. Identify potential hazards that could threaten the safety of your employees, customers, passengers, company facilities, company assets, customer property.

2. Rank the severity of hazards.

3. Identify current control measures.

4. Evaluate the effectiveness of each control measure.

5. Identify additional control measures.

One example of a system to proactively identify hazards is to establish groups to identify safety hazards by following five simple steps:

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Hazard Identification Program: Assess & Rank

Assess The Risk

Critically assess the risk associated with the hazard.

Factors to consider are the likelihood of the occurrence and the severity of the consequences.

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Hazard Identification Program: Hazard Controls

Identify The Hazard Control

Once the hazards are identified and the associated risk approximately ranked, hazard controls should be identified. The following illustrate how a hazard can be controlled.

– To prevent an unoccupied vehicle from rolling into an aircraft: Require all vehicles to be chocked, with the parking brake applied and in placed in “Park.”

– To prevent a fire at the fuel farm: “No Smoking” signs, routine inspections for electrical connections, leaks and debris, an effective foam suppression system, an emergency shutoff system, fire extinguisher, etc.

– Hazards identified at a particular airport: Ensure that operating procedures are properly documented and implemented.

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Hazard Identification Program

Evaluate The Hazard Controls

The appropriateness of the hazard control should be assessed.

– How effective is the hazard control?

– Does it prevent the occurrence (e.g., does it remove the hazard and eliminate or minimize the risk), or does it minimize the likelihood or the consequence?

– A control, once implemented, must be evaluated to ensure it minimizes the hazard and likelihood of occurrence.

– Example: Fire extinguishers are placed onboard an aircraft. Is the crew trained on their use and are the fire extinguishers properly maintained?

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Hazard Identification Program

Identify the need for hazard elimination, avoidance, or for further controls.

Each hazard and its control(s) should be critically examined to determine whether the associated risk is appropriately managed or controlled.

– If it is, the operation may continue.

– If not, improve the hazard control, or remove or avoid the hazard.

In some instances, a range of solutions to a risk may be available.

– Some may be engineering solutions (e.g., redesign), which are generally the most effective, but can be expensive.

– Others involve control (e.g., operating procedures) and personnel (e.g., training) and may be less costly. A balance must be found between the cost and practicality of the various solutions.

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Safety Risk Management & Safety Assurance Process

System/Task Analysis (5.1)

Identify Hazards (5.2)

Analyze Safety Risk (5.3)

Control/Mitigate Safety

Risk (5.5)

Assess Safety Risk (5.4)

Nonconformity

Preventive/Corrective Action (6.5)

Production/ Operational

System

System Assessment

(6.4)

Potential New Hazardor

Ineffective Control

Conformity

Sa

fety

As

su

ran

ce

Sa

f ety

Ris

k M

an

ag

em

en

t

Information Acquisition 6.3

Investigation (6.2.5)

Auditing (6.2.2, 6.2.3,

6.2.4)

Continuous Monitoring

(6.2.1)

Unacceptable

Acceptable

Analysis of Data/

Information (6.3)

Oversight Involvement? NoYesSend to

Oversight

Employee Reporting & Feedback

(6.2.6)

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Root Cause Analysis: IntroductionRoot Cause Analysis: Introduction

Fatigue origin of the failed tail rotor drive shaft coupling

ROOT CAUSE

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Root Cause Analysis

Root Cause: The most basic reason for an undesirable condition or problem which, if eliminated or corrected, would have prevented it from existing or occurring.

Wilson, Dell, and Anderson (1993), “Root Cause Analysis.”

Decision-Makers

Line Management

Organizational Preconditions, i.e., Company CultureLine Activities

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Root Cause Analysis

Wilson, Dell, and Anderson (1993), “Root Cause Analysis.”

Problem or Unwanted

Event Occurrence

Symptoms

Apparent Cause

Root Cause

Problem or Unwanted

Event Recurrence

Prevent

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Root Cause Analysis

There are many analytical methods and tools available for determining root

causes to unwanted occurrences and problems.

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Root Cause Analysis

The “5 Whys” Model

Fishbone Diagrams

Failure Modes Effects Analysis (FMEA)

TapRooT® Analysis

Useful Tools for Determining Root Cause

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Root Cause Analysis

For efficiency and ease of use, we will discuss:

• “5 Whys”

• Fishbone Method

Suggested Tools

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Root Cause Analysis

1. As a group, write down the problem and describe it completely.

2. Ask why the problem occurs and write down the answer.

3. If the answer you just provided doesn't identify the root cause of the problem that you documented in step 1, ask why again and write that answer down.

4. Return to step 3 until the team is in agreement that the problem's root cause has been identified.

– This process may take fewer or more than five whys.

The “5 Whys”

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Root Cause Analysis: “5 Why” Example

Event: You are operating a tug that is towing a Gulfstream IV. Suddenly, the tug becomes uncontrollable, which causes the tow hitch to break and extensive damage to the aircraft nose gear results.

1. Why did the aircraft become damaged?   - Because the tow bar hit the aircraft.

2. Why did the tow bar hit the aircraft?   - Because the tow hitch broke.

3. Why did the tow hitch break?   - Because the tug was uncontrollable.

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Root Cause Analysis: “5 Why” Example

4. Why did the tug become uncontrollable?   - Because the aircraft was being pulled with a tug rated below 10K draw bar pull.

5. Why was a tug with a rating that was below minimum being used ? - Because the tug operator was unaware of the guidance.

6. Why wasn’t the tug operator aware of the guidance?- Because the tug operator was new and had not been trained on the guidance.- Because the operator was unaware of the guidance.

7. Why hadn’t the employee been trained?- Because there are no procedures for processing new employees.

This process can go on if it is determined, via logical progression, that additional factors have a direct bearing on the outcome.

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Root Cause Analysis: “5 Why” Example

As you can see from the preceding example, asking why is an extremely

simple and effective way to determine root cause.

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Root Cause Analysis: Fishbone Diagrams

Man(People)

Machines

Mother Nature(Environment)

Methods

Materials

Measurements

Fishbone diagrams help to identify the “6 Ms” (potential causes) that may have contributedto the undesirable condition or problem.

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Root Cause Analysis: Fishbone Method

Great brainstorming tool!

Focuses on the cause, not the symptoms.

Identifies areas that may need further investigation.

Process can be enhanced by adding “5 whys.”

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Root Cause Analysis: Fishbone Diagram

Aircraft is damaged

1. Draw the diagram with the issue to be studied as the fish “head.”

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Aircraft isdamaged

2. Label each “bone” of the fish.

ManMachineMethods

Mother Nature

Materials Measures

Root Cause Analysis: Fishbone Diagram

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Aircraft isDamaged

3. Through brainstorming, identify factors in each category that could affect the undesirable occurrence.

ManMachineMethods

Mother Nature

Materials Measures

Gauge

Tug

Maintenance

Tools

Rain

Training

Driving

Tow Bar

Behavior

Manuals

Wind

Speed

Root Cause Analysis: Fishbone Diagram

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4. Upon completion of the fishbone, analyze the results.

5. Then, list the items that were identified in

priority order.

This brainstorming technique, when properly applied, can be helpful in determining a root cause to an undesirable condition or problem.

Root Cause Analysis: Fishbone Diagram

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Root Cause Analysis

Remember, the objective of root cause analysis is to identify the real cause of a problem, not the symptoms.

Hopefully, these simple tools will help you to do just that!