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What is root cause analysis

Root Cause =

  • The causal or contributing factors that, if corrected, would prevent recurrence of the identified problem
  • The “factor” that caused a problem or defect and should be permanently eliminated through process improvement
  • The factor that sets in motion the cause and effect chain that creates a problem
  • The “true” reason that contributed to the creation of a problem, defect or nonconformance

Root cause analysis is a standard process of :

  • Identifying a problem
  • Containing and analyzing the problem
  • Defining the root cause
  • Defining and implementing the actions required to eliminate the root cause
  • Validating that the corrective action prevented recurrence of problem

7 steps for effective root cause analysis and Problem Solving Process

7 steps for effective root cause analysis

Step #1 Identify the Problem

Clearly state the problem the team is to solve, teams should refer back to problem statement to avoid getting off track

Use 5W2H approach

  • Who? Individuals/customers associated with problem
  • What? The problem statement or definition
  • When? Date and time problem was identified
  • Where? Location of complaints (area, facilities, customers)
  • Why? Any previously known explanations
  • How? How did the problem happen (root cause) and how will the problem be corrected (corrective action)?
  • How Many? Size and frequency of problem

Step #2 Identify Team

When a problem cannot be solved quickly by an individual, use a team!

    • Should consist of domain knowledge experts
    • Small group of people (4-10) with process and product knowledge, available time and authority to correct the problem
    • Must be empowered to “change the rules”
    • Should have a designated Champion
    • Membership in team is always changing!

Key Ideas for Team Success

  • Define roles and responsibilities
  • Identify external customer needs
  • Identify internal customer needs
  • Appropriate levels of organization present
  • Clearly defined objectives and outputs
  • Solicit input from everyone!
  • Good meeting location

–  near work area for easy access to info

–  quiet for concentration and avoiding distractions

Roles and Responsibilities

  • Champion: Mentor, guide and direct teams, advocate to upper management
  • Leader: day-to-day authority, calls meetings, facilitation of team, reports to Champion
  • Record Keeper: Writes and publishes minutes
  • Participants: Respect all ideas, keep an open mind, know their role within team

Step #3 Immediate Action

  • Must isolate effects of problem from customer
  • Usually “Band-aid” fixes
  • Re-inspection before shipping
  • Rework if required
  • Recall parts/documents from customer or storage
  • only temporary until corrective action is implemented
  • must also verify that immediate action is effective
  • Must sure another problem does not arise from the temporary solutions

Step #4 Root Cause

  • Brainstorm possible causes of problem with team
  • Organize causes with Cause and Effect Diagram
  • “Pareto” the causes to identify those most likely or occurring most often
  • Use 5 Why? method to further define the root cause of symptoms

–May involve additional research/analysis/investigation to get to each “Why?”

  • Must identify the process that caused the problem

–if root cause is company-wide, elevate these process issues (outside of team control) to upper management to address

Tools used

  • Brainstorming
  • 5 Why or Five Why
  • 6M Analysis (Ishikawa/Fish bone diagram)
  • flowcharting
  • cause & effect diagrams
  • pareto charts
  • barrier analysis
  • change analysis
  • failure mode, effect & criticality analysis
  • fault tree analysis

Step #5 Corrective Action Plan

  • Must verify the solution will eliminate the problem, Verification before implementation whenever possible
  • Define exactly, What actions will be taken to eliminate the problem? Who is responsible? When will it be completed?
  • Make certain customer is happy with actions
  • Define how the effectiveness of the corrective action will be measured.
  • Verification–Assures that at a point in time, the action taken will actually do what is intended without causing another problem
  • Validation–Provides measurable evidence over time that the action taken worked properly, and problem has not recurred

Step #6 Follow Up Plan

  • What actions will be completed in the future to ensure that the root cause has been eliminated by this corrective action?
  • Who will look at what data?
  • How long after the action plan will this be done?
  • What criteria in the data results will determine that the problem has not recurred?

Step #7 Validate and Celebrate

  • What were the results of the follow up?
  • If problem did reoccur, go back to Step #4 and re-evaluate root cause, then re-evaluate corrective action in Step #5
  • If problem did not reoccur, celebrate team success!
  • Document savings to publicize team effort, obtain customer satisfaction and continued management support of teams

Note:

  • One problem may have more than one root cause
  • One root cause may be contributing to many problems
  • When the root cause is not addressed, expect the problem to reoccur
  • Prevention is the key!