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JOHN R. GROUT

CAMPBELL SCHOOL OF BUSINESS, BERRY COLLEGE

MOUNT BERRY, GEORGIA 30149-5024

JGROUT@BERRY.EDU

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