Reliability Engineering

Fred Schenkelbergfms@fmsreliability.com

ROOT CAUSE ANALYSISDay 3 Session 2

Objectives

• Examining different root cause techniques• Conducting incident investigations • Evaluating corrective actions• Advancing equipment troubleshooting• Failure reporting, analysis and corrective

action system (FRACAS)

Root Cause

• Initiating cause in a causal chain which leads to failure

• Depth of causal chain where an intervention is possible that changes performance or avoids failure

• Physical or Decision point

Root Cause Techniques

• Causation

• Forensic engineering

• Proximate & ultimate causation

• Root Cause Analysis

Technique Overviews

Causation

• Understanding of the system inputs as related to the output.

• Dependence – output values directly predictable by inputs to system.

Forensic engineering

• The investigation of materials, products, structures or components that fail or do not operate as intended

• The recreation of timeline of events leading to failure

Technique Overviews

Proximate and Ultimate Causation

• Proximate cause is the event which is closest to or immediately responsible for causing the failure.

• Ultimate cause is the real reason something occurred.

Root Cause Analysis, 8D

D0. PlanD1. Use a teamD2. Define and describe the problemD3. Develop Interim Containment Plan (implement and verify)D4. Determine, Identify and Verify root causesD5. Choose and verify permanent correctionsD6. Implement and validate corrective actionsD7. Take preventative measuresD8. Congratulate the Team

Discussion & Questions

Incidents

• An unplanned or undesired event that adversely affects operations

• Work related injuries• Occupational illnesses• Property damage• Spills• Fires• Near misses

Investigation

• Get the facts– Reporting– Data collection– No blaming…

• Determine root cause

• Recommend corrective actions

Poor examples

• It was Bill’s fault

• Insufficient budget

• No root cause – so must be deliberate error

• I was ordered to by pass safety equipment

Incident investigation process

• All incidents are investigated

• Corrective action determined to avert root cause

• Corrective action tracked till completed

• Trends reviewed, gaps identified and improvement plans implmented

Discussion & Questions

Corrective Actions

• Action in response or reaction to a failure

• Use root cause techniques

• Incident analysis

Predictive Action

• Proactive or prediction of problem and taking steps to avoid the failure

• Root cause analysis

• Risk analysis techniques

Examples

• Error proofing• Visible or audible

alarms• Product or process

redesign• Process control

improvements• Condition monitoring

Tactical & Strategic

• Tactical

• Immediate effects

• Local processes

• Physical causal chain interruption

• Strategic

• Cumulative effects

• Overall process

• Information causal chain improvements

Discussion & Questions

Troubleshooting

• Problem solving applied after a failure

• Logical• Systematic

• Determine the cause(s) of the observed symptoms

Troubleshooting Guidance

• Critical vs magical thinking

• Correlation vs causation

• Understanding what is supposed to happen

• Reproducible?• Intermittent causes• Multiple problems

Diagnostics

• The identification of the nature and cause of a failure.

• Focus on cause and effect

Diagnostic Guidance

• Black box recordings

• Condition monitoring information

• Sources of variation

• Theory of operation support

Discussion & Questions

FRACAS

• Failure Reporting Analysis and Corrective Action System

• Corrective and Preventive Action (CAPA) system

Purpose

• Provide closed loop failure reporting system

• procedures for analysis of failures to determine root cause

• documentation for recording corrective action

• Basic project management and prioritization

Poor examples

• Multiple systems

• No periodization – first reported first resolved

• Rewarding entries and completions

Discussion & Questions

Summary

• Examining different root cause techniques

• Conducting incident investigations

• Evaluating corrective actions

• Advancing equipment troubleshooting

• Failure reporting, analysis and corrective action system (FRACAS)

Root Cause Analysis