Root Cause Analysis

Root Cause Analysis - Overview • Root Cause Analysis • and • Corrective Action (RCCA) freeleansite.com

RCCA - Learning Objectives • The purpose of this module is to: • Apply the “5-why” technique in problem solving analysis. • Identify and understand the direct, contributing and root cause of a problem. • Learn the 2 types of corrective action. • Utilize a Corrective Action Matrix form to track and drive action item completions. freeleansite.com

Root Cause Analysis - An Overview • Root Cause Analysis and Corrective Action (RCCA) is a process for : • Finding the true cause(s) of an event • Identifying and implementing corrective actions • Assessing the effectiveness of corrective actions • Preventing recurrence of the events freeleansite.com

Why Root Cause Analysis ? • Integral part of Continuous Improvement • If we do not take action on problems, • we will be wasting our time and all involved • will lose interest. • Our Customers expect it ! • ISO 9001-2000 requirement • Makes good Business sense • Keeps us from passing on problems to • internal and external CUSTOMERS freeleansite.com

DMAIC process applied to RCCA Quantify Problem Control – Standardize Form Team Scope project Improvement RCCA Make Measure Improvement Analyze (Customer complaints, Audit findings, Production, Inspection Data, Product returns, Warranty etc) Investigate Root Cause freeleansite.com

Understand and State the Problem • Understand the Problem • From the event, what is the problem to • be solved, • or • what is the customer’s concern? • More than one Problem? • An event could have more than one problem, • with a root cause for each problem. • If you cannot say it simply, you do not • understand the problem! freeleansite.com

A Cause . . . • Is a set of circumstances or conditions that: • Allows a condition to exist or an event • to happen, • Or • Makes a condition exist or an event happen freeleansite.com

The Critical Five Direct Cause: The cause that directly resulted in the event. (The first cause in the chain.) Contributing Cause: The cause(s) that contributed to an event but, by itself, would not have caused the event. (The cause after the direct cause.) Root Cause: The fundamental reason for an event, which if corrected, would prevent recurrence. (Last cause in the chain.) freeleansite.com

The Critical Five Specific Corrective Action: Action(s) taken to correct or improve conditions noted in the event, by changing the direct cause or, The direct cause and the effect. Preventative Corrective Action: Action(s) taken that prevent recurrence of the condition noted in the event. (Preventive actions must directly address the root and contributing causes to be effective.) freeleansite.com

Root Cause/ Corrective Action • The process requires complete honesty and no • predetermined assumptions. • Follow the Data! Don’t try to lead it. • A common cop-out: “Operator error…” • Why do people not comply? • Improper instructions • Worn-out tools • Improper training • Lost expectations freeleansite.com

Root Cause/ Corrective Action • Don’t limit the search ! • What role did management systems play? • Are you looking beyond your own backyard? • Remember the 80/20 rule. • Be attentive to causes that show up frequently! freeleansite.com

Root Cause/ Corrective Action Utilize 5 Why’s technique for determination of cause and effect… Ask “Why?” 5 times. Most problems, even the most serious or complex, can be handled by using the 5 Why technique when coupled with cause chain diagrams. So, why use the 5 Why technique? freeleansite.com

Root Cause/ Corrective Action • Just keep asking … • Why did it happen? • Didn’t get to work on time. …… Why? • Car wouldn’t start. …… Why? • Battery was dead. …… Why? • Dome light stayed on all night. …… Why? • Kids played in car, left door ajar. • ….. Why? freeleansite.com

Root Cause/ Corrective Action • The 5 Why’s … another example – • Problem: “Customers complain about waiting too long to get • connected to staff during lunch hours.” • Why does the problem happen? • Backup operators take longer to connect callers. • Why does it take backup operators longer? • Backup operators don’t know the job as well as the regular operator/ receptionist do. • Why don’t backup operators know the job as well? • There is no special training, no job aids to make up for the gap in experience and on-the-job learning for back-ups. • Why don’t they have special training or job aids? • In the past, the organization has not recognized this need. • Why hasn’t the organization recognized the need? • The organization has no system to identify training needs. freeleansite.com

Poor control of manuf. process Don't know how to control the process Didn't understand implications of spec. Didn't achieve spec. first time The designs have been through several iterations Large volume of rework in PCB manufacture Boards difficult to make They're designed like that Operations take no responsibility for their work Operators make lots of mistakes They rely upon 100% inspection Decomposition Diagram • What it is: • Involves the use of tree structures to break down the area/process under study • A tree diagram where all items are included (comprehensively exhaustive) and not repeated (mutually exclusive) • When to use it: • Can be used as an analysis structure • Benefits: • Depicts a single dimension of hierarchy Operators poorly trained? freeleansite.com

“Why - Why” (5 Why’s) Analysis Problem Why? Why? Why? Why? Why? Poor control of manufacturing process Don't know how to control the process Didn't understand implications of spec. Didn't achieve spec. first time Large volume of rework in PCB manufacture The designs have been through several iterations Boards difficult to make They're designed like that Operators take no responsibility for their work Operators make lots of mistakes They rely upon 100% inspection Operators poorly trained? … suited to both Repetitive and Non-Repetitive Processes freeleansite.com

“Why - Why” (5 Why’s) Analysis • What it is: • A combination of a decomposition diagram and cause and effect diagram in tree diagram format that shows the linkages between an effect and its root cause • When to use it: • When a cause and effect diagram has been built and the primary causes have been identified, the 5 whys is used to delineate the causal linkages between the final effect and the originating root cause. ** Don’t be limited to only 5 whys: the end point is the root cause • Benefits: • Establishes the evidence chain (or the hypothesis thereof) so that confirming facts and data can be collected to substantiate the sequence and the critical dependencies between relationships and time sequences • Disciplines the problem solving team to critically examine assumptions and evidence in order to support the relationships between each link. “How do you know??” freeleansite.com

Case of a Broken Photocopier freeleansite.com

Root Cause/ Corrective Action Direct Cause: The cause that directly resulted in the event. (The first cause in the chain.) THIS IS THE ANSWER TO YOUR FIRST QUESTION. (YOUR PROBLEM STATEMENT) Contributing Cause: The cause(s) that contributed to an event but, by itself, would not have caused the event. (The cause after the direct cause.) Note: For a simple problem there may not be any contributing causes. Root Cause: The fundamental reason for an event, which if corrected, would prevent recurrence. (Last cause in the chain.) freeleansite.com

The Cause Chain RCCA Root Cause Contrib. Cause Direct Cause Contrib. Cause EVENT freeleansite.com

Root Cause Analysis Let’s expand on a problem … Cause and Effect Received ticket for safety violation - Car exhaust too loud - Muffler knocked loose from tailpipe - Daughter hit pot hole - Pot holes in road - Winters damage roads - Congress won’t approve extra money for better roads - Congress doesn’t have extra money - Congress spend money on pork barrels - Too many lawyers in Congress Solution? Drive in Sweden, where there are fewer Lawyers. freeleansite.com

Root Cause Analysis Utilize appropriate toolset with the team. Uncover the root cause. Test and formulate corrective action. Examples: • Brainstorming, Pareto analysis, Cause and Effect analysis, X-Y matrix • Process audit, Benchmarking • Consensus, mistake proofing (poka-yoke) • Statistical analysis, quality function deployment • Opportunity for simplification - Integration and standardization (refer to VE & VA module) freeleansite.com

Root Cause/ Corrective Action • Corrective Action: • A set of planned activities (actions) implemented for the sole purpose of permanently resolving the problem. freeleansite.com

Root Cause/ Corrective Action • Two types of Corrective Action: • Specific • Preventive • These two types of corrective action are quite different in how they are applied and what they do. Not understanding this leads to serious mistakes in fixing problems. freeleansite.com

Root Cause/ Corrective Action • Specific Corrective Action: • Action(s) taken to correct the direct cause. • (Corrects, or improves the condition noted in the • event, by changing the direct cause, or the direct • cause and effect.) • Sometimes called containment • Only used to correct the DIRECT cause • Does not prevent recurrence ! freeleansite.com

Root Cause/ Corrective Action • Preventive Corrective Action: • Preventive corrective actions focus on changing • the root cause and any contributing cause(s). • You probably won’t get a 100% effective fix at just one point (the root cause). • You often have to consider two or more contributing causes to ensure the chain is broken. freeleansite.com

Root Cause/ Corrective Action • Preventive Corrective Action: • Action(s) taken prevent recurrence of the • condition noted in the event. (Preventive actions must directly address the root and contributing causes to be effective.) freeleansite.com

Preventive Corrective Action X Root Cause X Contrib. Cause Direct Cause X Contrib. Cause EVENT freeleansite.com

Root Cause/ Corrective Action • Test the specific solutions to ensure they are valid: • Do the corrective actions eliminate or control the direct cause? • Are the results desirable? freeleansite.com

Root Cause/ Corrective Action • Example (ask Team) freeleansite.com

Root Cause/ Corrective Action • Preventive Action Test: • If these preventive corrective actions were in place, would the event have occurred? • Are there adverse effects caused by implementing the corrective actions that make them undesirable? • Do the preventive corrective actions lower the risk factor of the event to an acceptable level? freeleansite.com

Root Cause/ Corrective Action • Basic elements of reporting: • Restatement of the problem/ event/ objective • Data (who, what, where, why, how, etc.) • Team (natural work group, qualified) • Causes (root, direct, contributing) • Corrective Actions (specific, preventive, plant-wide) • Milestone dates (Analysis complete, C/A initiated, C/A implemented, Corrective Action Report closed) • Follow Up (Is implementation, solution acceptable?) freeleansite.com

Tracking Form - example Basic tracking form – Corrective Action Matrix (CAM) Refer to - webpage (tools) freeleansite.com

Tracking Form - example NOTE: Blank form located on free lean site freeleansite.com

Root Cause/ Corrective Action Follow-up A review must be conducted in sufficient detail to assess whether the corrective actions that have been implemented are effective as implemented and are truly preventing recurrence of the event. freeleansite.com

Root Cause/ Corrective Action • Effectiveness Measures • The criteria used to evaluate if the corrective actions achieved the desired outcome. • Examples: • Scrap quantities significantly reduced • Print was not manufactured to print tolerance. After corrective action, part meets print. • Design could not be manufactured with current technology. After corrective action, part can be manufactured with current technology. • Parts would not assemble properly. After corrective action, parts would assemble properly. freeleansite.com

Root Cause/ Corrective Action • Did corrective actions work? • Some additional things to consider: • If corrective action implemented differs from proposed, • find out why. • If better or alternate corrective actions were implemented, document the changes. • Periodic checks may be necessary to be sure the corrective actions are still in place. • Document using the proper forms. freeleansite.com

Root Cause Analysis - Overview • Root Cause Analysis • and • Corrective Action (RCCA) freeleansite.com

Root Cause Analysis - Overview