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JOHN R. GROUT
CAMPBELL SCHOOL OF BUSINESS, BERRY COLLEGE
MOUNT BERRY, GEORGIA 30149-5024
Mistake-Proofing and Lean Methodology
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It’s all about the process
Introduction to Lean
Mistake-proofing
“Process: a collection of interrelated work tasks,
initiated in response to an event achieving a
specific result for the customer and other
stakeholders.”
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Value stream
The value stream is the set of all the specific actions
required to bring a specific product through the three
critical management tasks of any business…
Problem solving:
concept designlaunch
Information management:
order takingschedulingdelivery
Physical transformation:
raw material Finished good
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Muda: 7 wastes
1. Overproduction. (stop doing work early, decreasing
length of stay)
2. Waiting (waiting rooms should shrink)
3. Transporting (Park Nicollett cancer facility)
4. Inappropriate Processing (over-treating (Brownlee)
5. Unnecessary Inventory (minimal inventory & shrinking
storerooms)
6. Unnecessary / Excess Motion (lower shift distance
walked)
7. Defects
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Value?
What exactly are you paying for?
• Driving to the airport
• Parking at the airport
• SLC to LAX to ATL
• Biscoff cookies
• Waiting for bags at baggage
claim
• Waiting to be “roomed”
• Walking from one end of
hospital to other?
• Nurse looking for a wheel
chair or supplies
• Waiting to be discharged
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Flow
After waste is eliminated
Create flow
Everything should move immediately from one process step to the next
uninterrupted (one-piece flow)
Patients and materials should start to flow as if they were the only one in
the hospital (or through the architectural firm).
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Pull
• Have parts continually ready,
in limited supply.
• Avoid or trivialize scheduling
• Avoid customer waiting
• Replace what is taken
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Perfection
1. Doing the first 4 steps (value, value stream, flow and
pull) reveals new more precise views of waste.
2. Since the pay off for eliminating waste is so high, and
has been demonstrated to be an achievable goal…
3. The newly revealed waste becomes low-hanging fruit
for improvement.
4. Go to 1. Repeat.
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MISTAKE-PROOFING: BUILT-IN TESTS OF SUCCESS
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Mistake-proofing is …
The use of process design features to prevent simple errors or their negative impact.
Also known as Poka-yoke, Japanese slang for “avoiding inadvertent errors.”
Inexpensive & effective.
Something already in use in healthcare, but more could be done.
Examples:
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Stairwells should not
allow users to
descend below the
level of the exits
without a strong cue
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Visibility of process
status helps improve
satisfaction and
efficiency.
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Communicating with Linoleum
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Broken seal triggers
supply restocking
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Standardized Head Wall
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Example
Way-Finding in Hospitals
Colored lines or icons on the wall or floor show the way to various departments.
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Q: (Wall Street Journal) How are you
going to design restroom facilities In
JFK International Terminal to
reduce spillage??
A: (you pick) One of the following
A) Hire an attendant to monitor and reprimand “less
hygienic” users
B) Periodically plot spillage area on a statistical control
chart, perform root cause analysis when unusual
variation occurs
C) Double the size of the fixtures
D) Etch the image of a fly on the porcelain
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Interdisciplinary approach
to design
Engineering:
Petroski says “We rely on failure of all kinds being
designed into many of the products we use every day, and
we have come to depend upon things failing at the right
time to protect our health and safety... We often thus
encourage one mode of failure to obviate a less desirable
mode.”
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Interdisciplinary approach
to design
Psychology:
Norman recommends designing forcing functions into
process: “actions are constrained so that failure at one
stage prevents the next step from happening.” “[they] rely
upon properties of the physical world for their operation;
no special training is necessary”.
“Knowledge in the Head” vs.
“Knowledge in the World”
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Interdisciplinary approach
to design
Medicine:
“…a process that is designed to detect failure and to interrupt
the process flow is preferable to a process that continues on
in spite of the failure…We should favor a process that can, by
design, respond automatically to a failure by reverting to a
predetermined (usually safe) default mode.
Croteau & Schyve, Proactively Error-Proofing Health Care Processes, in Spath,P.L., Error Reduction in Health Care. Chicago: AHA Press, 2000.
Note that interruptions are themselves process failures
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Designing failures?
Failure mode and effects analysis (FMEA)
and other failure analysis methods now
have TWO purposes.
1. Determine causes of undesirable failures, and
implement preventive measures
2. Determine ways of creating benign failures, and
use them AS preventive measures
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Designing failures?
OR
Harmful Event
AND
Cause
#1
P(F1)=.1
Cause
#2
P(F2)=.1
Cause
#3
P(F3)=.05
P(C1C2)=.01
P(harmful event)=.11 OR
Benign Failure
AND
Cause
#A
P(F1)=.1
Cause
#B
P(F2)=.1
P(C1C2)= .001
Cause
#C
P(F2)=.1
Cause
#4
P(F4)=.05
Grout, “Preventing Medical Errors by Designing Benign Failures.” Joint Commission Journal on Quality and Safety Vol. 29 (2003), No.7, pp. 354-362.
Cause
#4
P(F4)=.05
P(Benign Failure)= .051
X
P(harmful event)=.06
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5 stories high
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Still Seeking Examples
Manufacturing: 4 books with
approximately 500 examples
Healthcare: 1 book with 150
examples
Architecture, engineering and
construction: 0 books (1
manuscript in progress) with
100+ examples, mostly
construction.
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Send me examples
like this:
Color coded walls
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Or this:
Preventing the
influence of mistakes
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This would work too:
Mistake prevention in
the work environment
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Even this would be deeply appreciated:
Mistake prevention in future repairs
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Here’s another: Preventing the influence of mistakes
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Send everyday
examples that apply:
Mistake detection
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Or this:
Metal sensing drill
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Here is an example that was provided by a firm in Vermont:
Mistake detection
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But DO NOT send me this:
What’s wrong with this picture?
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Thank You