root cause examples (i)

7/30/2019 Root Cause Examples (I)

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1© 2004 Superfactory™. All Rights Reserved.

Manufacturing

Root Cause AnalysisExample #1




Example #1

Identify Problem

Part polarity reversed on circuit board




Immediate Action

Additional inspection added after this assembly processstep to check for reversed part defects

Last 10 lots of printed circuit boards were re-inspected to

check for similar errors




Root Cause

Part reversed

Why?




Root Cause

Part reversed

Worker not sure of correct part orientation

Why?




Part is not marked properly

Root Cause

Part reversed


Why?


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Engineering ordered it that way from vendor


Root Cause

Part reversed


Why?




Process didn’t account for possible

manufacturing issues

Engineering ordered it that way from vendor


Root Cause

Part reversed





Corrective Action

Permanent – Changed part to one that can only be placed in correct

direction (Mistake proofed). Found other products with similar problemand made same changes.

Preventive - Required that any new parts selected must have

orientation marks on them.




Example #2

Identify Problem

A manager walks past the assembly line and notices a puddle of water on the floor. Knowing that the water is a safety hazard, sheasks the supervisor to have someone get a mop and clean up thepuddle. The manager is proud of herself for “fixing” a potential

safety problem.




Example #2

But What is the Root Cause?

The supervisor looks for a root cause by asking 'why?’




Immediate Action

Knowing that the water is a safety hazard, the manager asks thesupervisor to have someone get a mop and clean up the puddle.




Root Cause

Puddle of water on the floor

Why?




Root Cause


Leak in overhead pipe

Why?




Water pressure is set too high

Root Cause



Why?




Water pressure valve is faulty


Root Cause



Why?




Valve not in preventative maintenance program

Water pressure valve is faulty


Root Cause






Corrective Action

Permanent – Water pressure valves placed in preventativemaintenance program.

Preventive - Developed checklist form to ensure new

equipment is reviewed for possible inclusion in preventativemaintenance program.




Example #3





Example #3

Identify Problem

Customers are unhappy because they are being shipped

products that don't meet their specifications.




Immediate Action

Inspect all finished and in-process product to ensure it meetscustomer specifications.




Root Cause

Product doesn’t meet specifications

Why?




Root Cause


Manufacturing specification is different from

what customer and sales person agreed to

Why?




Sales person tries to expedite work by calling

head of manufacturing directly

Root Cause




Why?




Manufacturing schedule is not available for

sales person to provide realistic delivery date



Root Cause




Why?




Confidence in manufacturing schedule is not

high enough to release/link with order system

Manufacturing schedule is not available for

sales person to provide realistic delivery date



Root Cause







Root Cause



Why?




Root Cause



Parts sometimes not available thereby

creating schedule changes

Why?




Expediting and priority changes consume

parts not planned for

Root Cause





Why?




Manufacturing schedule does not reflect

realistic assembly and test time



Root Cause





Why?




No ongoing review of manufacturing standards

Manufacturing schedule does not reflect

realistic assembly and test time



Root Cause








Corrective Action

Permanent – Manufacturing standards reviewed andupdated.

Preventive - Regular ongoing review of actuals vs

standards is implemented.




Example #4

Identify Problem

Department didn’t complete their project on time




Immediate Action

Additional resources applied to help get the project teamback on schedule

No new projects started until Root Cause Analysiscompleted




Root Cause

Didn’t complete project on time

Why?




Cause and Effect

Didn’t complete

project on time

EquipmentMaterials

PersonnelProceduresLack of worker

knowledge

Poor project

mgmt skills

Poor project plan

Inadequate

computer

programs

Inadequate

computer system

Poor

documentation

Lack of resources




Root Cause


Resources unavailable when needed

Why?




Took too long to hire Project Manager

Root Cause



Why?




Lack of specifics given to

Human Resources Dept


Root Cause



Why?




No formal process for submitting job opening

Lack of specifics given to

Human Resources Dept


Root Cause






Corrective Action

Permanent – Hired another worker to meet needs of nextproject team

Preventive - Developed checklist form with HR forsubmitting job openings in the future




Example #5





Example #5

Identify Problem

High pyrogen count on finished medical catheter product using

molded components.




Immediate Action

Immediate Action (and panic!)

Quarantine all finished and in-process product

(over $2 million worth!)

Analyze location of pyrogen to find common denominator




Panic-Driven Action

Panic-driven Immediate Reaction(without root cause analysis)

Pyrogen traced to molding cooling water leak Holy cow!… cooling water system hasn’t been cleaned in 15 years! Shut down 24/7 molding operation for 2 days to clean cooling water system Implement system for weekly analysis of cooling water for pyrogens Threaten to fire anyone who doesn’t report a cooling water leak




Panic-Driven Action - Results

Results of Panic-driven Immediate Reaction(without root cause analysis)

Day 1 after cooling water system cleaning: water tests clean of pyrogens

Day 2: cooling water is saturated with pyrogens. Uh oh.

All operators and technicians reporting “possible water leaks” onall presses, all molds, all shifts… “just in case”.

Molding operation shuts down. Operations manager nearly fired.

“Help” flying in from corporate offices and other molding plants. Hourly conference calls to give status updates to executives.




Logic Returns

There must be a better way! How about trying something called “Root Cause Analysis”?




Root Cause

Pyrogens on molded components

Why?




Root Cause


Parts released from molding even though they

had been sprayed with leaking cooling water

Why?




Disposition of contaminated parts procedure

does not discuss water

Root Cause




Why?




Oil, grease, dust, human contact believed to

be primary sources of contamination



Root Cause




Why?




No formal evaluation of contamination sources,

types, severity, and disposition action.

Oil, grease, dust, human contact believed to

be primary sources of contamination



Root Cause






Corrective Action

Permanent – Disposition of contaminated parts procedurere-written to include water.

Preventive - Formal study of contamination sources,consequences, and disposition requirements.

root cause examples (i)

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