|
The Red Bead Experiment
Introduction
This experiment can be conducted with a Sampling
Bowl or Sampling Box. While
Dr. Deming used 80% white beads and 20% red, you will find this
experiment done with 80% white and 20% colored. The colored beads
add another dimension to the demonstration. This will be become
self evident as the script is read.
This is a clever demonstration of the futility of most management
systems for improving quality. Dr. Deming often refers to it as
a stupid experiment that you'll never forget. The experiment is
described in a form similar to Dr. Deming's presentation in his
seminars. As will be described at the end, it can also be adopted
for very small groups and even a one on one presentation.
The experiment starts with a sampling device that has 80% white
and 20% colored beads, normally red beads, hence the name "red
bead experiment". The fact that the some sampling devices
have various colored beads instead of all red is of no consequence,
the experiment works just as well. It is necessary however to
have 20% colored beads to go along with the text of this demonstration.
If different colored beads are used instead of all red, then the
colors can represent different kinds of defects. (This will become
clearer as the demonstration is described.)
The objective of the bead factory in the demonstration is to
make white beads. The customer will not accept anything but white
beads, all colored beads are defective. The colored beads themselves
represent defects in an organization's business processes. They
represent a faulty machine or tool, a bad engineering design,
a defective part, a procedural flaw, an unreasonable change request,
... all the things that can and do go wrong with a process. Supervisors
and management control the number of red bead in the processes
that are given to the workers. Now. let's proceed assuming that
management has developed and purchased the white bead process
for the workers of this experiment.
The Experiment
The instructor should take on the role of the department foreman
or department supervisor and first of all selects his work team.
Realizing that one of the objectives of this demonstration is
to point out management prejudices, the instructor can use whatever
slogans or phrases he believes fit his particular audience. It
many start like the following.
Foreman: Okay I need eight bodies. (Pointing to people
he wants to select) Can you count? Okay you're hired . Can you
push buttons? Okay you're hired. You don't have to think, you
just have to do what I tell you. You'll be on an apprenticeship
for a while and if you work out we'll hire you. We believe in
high quality. We need good people.
So the process goes until all nine people are selected. The roles
they will perform are as follows:
Back to top
What will happen is that each worker will take turns drawing
a sample of 50 from the sampling device. If you are using a sampling
bowl then use the 50 hole paddle. If you are using a sampling
box then designate the 50 hole pattern that you will use. This
can be done verbally, mark on the face of the box with a water
based transparency marker, or mask off the excess holes with masking
tape, etc. Once a sample is drawn, then it will be checked by
both inspectors (this high quality company has 200% inspection)
who will independently write down the number of colored beads
they count and show it to the chief inspector. The chief inspector
will compare the counts, record the information on a data sheet
and a graph, and then announce the number of colored beads drawn
in the sample. The data sheet will show the names of the six workers
and how many colored beads they each draw for the four days of
the experiment. The data sheet will look like the sample data
shown in figure 1. The graph will have six plot points for each
day for four days and look like the graph in figure 2. These graphs
can be set up on chart pads or overhead transparencies.
After the samples are counted, the beads are returned to the
sampling device and another sample is drawn (shaking the box or
mixing the bowl adds to the demonstration). Obviously the percent
defective is a constant 20% but the actual percentage will vary
with each sample due to sampling error and this is where the spoof
begins. While there are some lessons in statistics than can be
taught from this experiment, the real punch line is in the way
the instructor conducts the demonstration and allows people to
see themselves and the futility of management practices for improving
quality. Each instructor has to know is audience and how far he
can push his points without turning them off.
As the experiment is carried out over the four days the instructor
uses the results of the samples to make his points. Realizing
that the data will most likely vary between 1 and 19 (determined
from the control chart calculations for UCL and LCL for a process
that is 20% defective and sample sizes of 50). There are a variety
of points that can be made. The exact order that the instructor
will make the points will be dependent on the actual data developed
in the experiment. However, after 24 samples you will have enough
high and low readings along with increasing and decreasing trends
to make all the points.
Back to top
Clear Instructions
The first point of the demonstration has to do with giving clear
instructions. Management often believes that if they make the
objectives clear then the problems will go away. It could go something
like the following:
Foreman: Bob you know that our job is to make white beads,
the customer will not accept colored beads. You make white beads
by first of making sure that the material is well mixed. If it
is not mixed well you will have trouble making white beads. (Demonstrate
how you want the box shaken or the beads mixed in the bowl) You
then turn the box over and hold it completely flat while you push
this button on the end and white beads will fall into the holes.
(If you are using a sampling bowl then the describe how the paddle
is to be used to draw a sample.) Place the paddle into the bowl
at the end, scoop deep into the beads and raise the paddle slowly
at an angle of precisely 30 degrees and let the extra beads roll
off the paddle. Now I've described the job for all you very clearly.
I'm sure that all of you can now make white beads. Bob, would
you please make our first batch of white beads.
Bob draws the first sample and shows it to the inspectors who
record the count and they show it to the chief inspector. He then
announces that we have 14 red beads. If colored beads are used
then let red beads be red defects, green be green defects, yellow
be yellow defects, etc. Still have the chief inspector count and
record the total number of colored beads, but have him also report
the different number for each color. The instructor can then use
this to attach more blame to the worker, i.e. "Yellow defects,
you know they are the worst kind and most costly to repair,"
and so on.
Foreman: Bob I've told you that the customer will only
accept white beads, colored beads are not acceptable. Did you
mix the material and hold the box completely flat like I told
you? (Did you hold the sampling paddle at precisely 30 degrees?)
Bob: Yes I did
Foreman: Well you must not have been paying attention.
Dorothy can you please make us a batch of white beads? Remember
all that I've told you. (Repeat the appropriate instructions again).
Dorothy draws a sample and it comes out to be 12 colored beads.
Foreman: Well Dorothy that is better than Bob, but you
must not have been paying attention either. Let me repeat the
instructions once again. (Repeat the appropriate instructions)
Henry will you please run this process. Remember that the customer
will only accept white beads.
Intimidation
Henry then draws a sample and it comes out to be 15.
Foreman: Henry I need to talk to you. Didn't you hear
me when I gave all these people instructions on how to make white
beads? What were you doing at the time, dreaming of some date
you were going to have with Judy? I thought you said you wanted
a job. We bring you here, give you clear instructions, show you
how to make white beads and you still don't do it. What's the
matter with you? Now I'm telling you people, you all better start
paying attention or I'll have to fire all of you. Calvin it's
your turn.
Praise and Comparison
Calvin draws a sample and it comes out at 8 colored beads.
Foreman: Now that's much better. Calvin you are catching
on. Calvin got the same instructions as the rest of you and he
is now beginning to master the process. He was almost twice as
good as Henry. We are going in the right direction now. Henry,
you especially need to watch Calvin and see how he did it. In
fact, the rest of you should all watch Calvin and see how he does
it. Carol, it is your turn.
Back to top
Banners and Slogans
Carol draws a sample and it turns out to be 10.
Foreman: Carol, I told you to watch Calvin. He knows how
to do it. Now all of you listen up. We have firm quality standards
at this factory. Didn't you read the quality first banner over
the door of the factory? See that poster on the wall over there,
it says "Satisfied customers are happy customers and that
means they will buy more." Quality is critical to our survival
as a company and you know what that means for all our jobs. This
company has to get the silver star quality award. It is crucial
to our success in the market place. Judy please show us how it's
done.
Judy draws and sample and it come out to be 6. The foreman then
walks over and talks to the chief inspector.
Foreman: Darwin, here is a prime example of quality improvement.
You see once I pointed out to everyone that we are really serious
about quality at this factory, people started to improve. Judy
ran the best batch of white beads that we've seen so far. I think
that we need to put a poster by everyone's machine instead of
just a few on the wall that we have. You know if we buy some of
those quality first buttons we all could wear one and give one
to every employee that improves. I'm sure that we can drive the
point home more about quality. While today wasn't the best I'm
sure we'll do better tomorrow. (While walking over to Judy) Judy,
excellent job. Keep up the good work.
Incentives
Tomorrow comes and the foreman asks Bob to run his batch of white
beads. Bob runs his sample and it comes out at 10.
Foreman: Bob you've done better than you did yesterday
but we are still going in the wrong direction. I've talked this
matter over with our management and we are going to institute
a quality bonus for everyone who runs good parts. If you guys
and gals will all do better we will have a big pizza party and
bonus for everyone.
After the bonus scheme is in place Dorothy draws 5, Henry draws
6, and Calvin draws 8 colored beads. The foreman then talks to
the audience as if they were the management. He is explaining
the value of the bonus scheme.
Foreman: Well after we instituted the bonus scheme that
I recommended things got better immediately. While things have
been going up and down we are still much better than we were yesterday.
I think that our people are finally getting the message and all
our efforts with the new quality banners and quality first buttons
are paying off. We are definitely on the road to zero defects.
I think that we should design another button with a big zero in
the middle that is surrounded by gold stars that we can present
to our best employees. In fact I would like for one of you to
speak at our employee meeting and tell them about this exciting
new zero defects button program.
Back to top
Blame
Carol and Judy then each draw 11 colored beads. The foreman is
very upset that things are going bad after he has told management
that things were improving. He then goes over to the chief inspector
and discusses the problem with him.
Foreman: Darwin, I'm really upset. These people don't
care. Here you give them a good job and show that it is possible
to improve and what do they do, ignore you and make life easy
for themselves. I know that our incentive scheme was working,
look at the results. I think Carol and Judy are spending too much
time talking to one another and not paying attention to their
job. I think that I'll warn both of them about their performance
and tell them if I catch them talking again that I'll have to
discipline them.
Performance Appraisals
This process continues again and again until all 24 samples have
been taken. The data is then summarized for display and the supervisor
then rates everyone's performance. The data is then placed on
an overhead projector or summarized on a chart pad.
Foreman: Bob, you started off bad and then improved slightly.
You have got to do better. Dorothy, you started off bad, then
you improved, then you fell off the wagon again, and then improved
again. You need to pay closer attention to your work and gain
more consistency. Henry, you started off terrible and then you
finally caught on. You have the same problem as Dorothy, you need
more consistency. Calvin, your the best employee in the department,
but you still have room for improvement. You could be the first
employee to earn the zero defects button that the manager talked
about at the employee meeting. Carol, your performance needs to
improve. Your overall rating was good. You can do better if you
stop all that talking with Judy I warned you about. Judy, you
need to pay attention to your work. You started off good and something
must have distracted you. I think it was all the talking with
Carol.
The foreman should now take on the role of explaining the results
to management as he turns to the audience. The focus can now be
on the graph and the noting of the various trends. The same praise
and blame is offered for the trends. An evaluation of the trends
for each day and an overall comparison of each of the workers
may be appropriate at this point, as you try to present the results
with the best possible explanation. The supervisor would then
promise that they can do better and explain all the new quality
programs that are in place to address the problems, i.e. posters,
etc. He would make special note that he had warned the Judy and
Carol and gave them unfavorable performance evaluations.
Discussion of the Experiment
The instructor then steps out of his foreman role and now asks
questions as an instructor in order to get the class to evaluate
what has happened.
What was the average of number of defects for the experiment
(X-Bar)? Take the total number of colored beads(220) and divide
by 24. (X-Bar=220/24=9.2 for this experiment) Ask them what they
expected the average to be and why. Facilitate a discussion that
gets them to see that the average has got to be 20% defective
since we know that there was a fixed 20% defective all the time
in the sampling device. Explain that "p bar" is merely
the average percent defective for a given sample size. Given that
we had 20% defective, and samples of 50, 20% of 50 is 10. In our
example the actual average was 9.2. This will vary slightly with
each demonstration.
Back to top
Next show that a simple p-Chart would have control limits of
1 and 17. This is determined by using the following formulas:
P Bar = 220 / 6 * 4 * 50 = .18
UCL or LCL = X Bar ± 3 Sq Root
[(X-Bar)(1-P Bar) ]
9.2 ± 3 Sq Root [(9.2)(.82) ]
=
or
9.2 ± 8.24 = .96 to 17.44
What this means is that given a 20% defective process, and with
sample sizes of 50, that the number of colored beads will vary
over 99% of the time between 1 and 17 just due to random chance.
In the demonstration we knew that it was random chance because
we controlled the experiment by virtue of a constant number of
beads. In actuality, we have what Dr. Deming calls a "stable
process," or a system that is varying only because of random
chance. This random chance is also referred to as only being affected
by "chance or common causes." Note that a stable process
may still turn out faulty items.
Back to top
While there are a number of options for discussing the results
of the experiment, the instructor can discuss the following points
independently or use the Deming's 14 points slide in the appendix
as a guideline.
Using the 14 point slide as a reference, add the following comments
for each respective point:
Dr. Deming's Fourteen Points
1. Create constancy of purpose for improvement of product
and service. The red bead experiment is a process. The only
way to actually improve the process was to change the number of
red, or colored beads, in the container. While the process the
data varied showing good and bad trends, the foreman was deceived
into thinking his actions were impacting the process when in fact
only random variation was taking place. The focus of improvement
has to be on changing business processes, not blaming people.
2. Adopt the new philosophy. Management controls the number
of red beads in a process initially since they design the products,
purchase the machines or facilities, and establish the operating
procedures. Once a system is in installed, management has to find
a way to reduce the number of red beads if they want to improve
the process. The problem is, that in most cases management does
not know where the red beads are, but the workers do. It is only
through a joint effort between management and workers that processes
can be improved.
3. Cease dependence on inspection to achieve quality.
While two inspectors counted the number of red beads, you can
note how often the count may have differed. Point out the non-value
added role of the inspectors in actually changing the process.
5. Improve constantly and forever every process for planning,
production, and service. The number of red beads in this experiment
causing the level of variation was totally controlled by management.
The workers were totally helpless in affecting the number of red
beads that were drawn. In real life however there usually are
some things that the workers can do to create improvement. But
according to Dr. Deming common or chance causes are controlled
my management (usually 85% of the problem), and local faults or
special causes (15%) are controlled by workers. Hence the major
responsibility for process improvement (85%) lies with management
changing the systems.
6. Institute training on the job. Point out how a simple
understanding of p-chart statistics would have helped the foreman
recognize that the process was really a stable process and that
the variation he was experiencing was really normal and expected.
While the foreman gave clear instructions of what was expected
to the workers on the first day, this alone did not create quality.
Management clearly telling workers what they want does not mean
that workers can achieve it.
8. Drive out fear. If management really wants to learn
where the red beads are in a process so they can remove them,
they must be willing to listen and stop blaming workers for poor
results. Did the intimidation or comparisons of the workers have
any real affect on the outcome of the red bead experiment? Management
thought so at the time, but in reality the results were still
caused by random variation.
10. Eliminate slogan, exhortations, and targets for the workforce.
In the same way that intimidation and comparisons between workers
did not impact the outcome of the red bead experiment, neither
did the slogans, buttons, or incentive schemes. The understanding
and focus has to be on the process and it's capabilities.
12. Remove barriers that rob people of pride of workmanship.
Eliminate the annual rating or merit system. How do you think
the workers felt about their performance appraisals? Do you think
that it motivated them to do better? Has anyone ever had a performance
appraisal where the comments were similar to same mumbo jumbo
and clichés that were fed to the workers in this experiment?
14. Put everyone in the company to work to accomplish the
transformation. If management does not actually solicit employee
input on solving business processes they are passing up a golden
opportunity for improvement. Everyone at all levels of the organization
has to be focused on quality improvement.
In summary, this demonstration can be a lot of fun while still
making a number of dramatic points. The use of participants keeps
people involved and active. If you get involved and act out the
roles, the class will do likewise. The more the instructor customizes
the experiment to the class the better it will be received. Use
phrases that are common to the work place. Finally, the power
of the experiment is only limited to the creativity of the instructor.
Adaptations of the Experiment
Small Audiences - The previous description was designed
for classroom use. There may be situations were it would be advantageous
to perform the experiment on a smaller scale and more quickly.
To abbreviate the experiment assume that the conversations take
place between the foreman and one employee. Explain the requirements
and then let the employee begin sampling. As data will of course
immediately show red beads, the various management solutions can
be stated to the employee. Cover the following issues between
each sample like intimidation, unfair comparisons, praise, banners
and slogans, providing incentives, and blame. Record the results
of each sample and then give the person a performance appraisal
at the end. Discuss how the employee felt as you were explaining
to him all the management solutions for improvement.
Use of a Customer - Instead of having two inspectors and
a chief inspector let one person review the bead sample who will
be the customer. Pre-arrange with the customer to act like an
irate customer when he gets different colored beads, etc.
Rework Department - If you are using a sampling bowl and
would like to make a point about the cost and inconvenience of
rework pick another worker to be a rework operator. Give them
a bottle of white out correction fluid and tell them to paint
some of the red beads white. Note that this can be messy and you
need to also have a bottle of correction fluid solvent and a rag
available for clean up of the operator and the beads when you
are finished. Letting them work on three to four beads will be
sufficient. Make the point about how poor a job they have done
in rework. Show the production workers all the problems they have
caused. Let the inspectors or customer comment on the quality
of the rework job.
Bead Box versus Sampling Bowl - While both devices can
be used for demonstration purposes each has its own advantages.
The bead box is of course totally self contained and is easily
transported. Students can handle and play with the box as it is
passed around. The Sampling Bowl on the other hand is very visual
and works well with large audiences. It provides flexibility in
determining the colors and percentages as well as sample sizes,
etc. As previously mentioned, different colored beads can be used
to represent different types of defects and problems
Back to top
The Fourteen Obligations
of Top Management
1. Create constancy of purpose for improvement of product and
services.
2. Adopt the new philosophy.
3. Cease dependence on inspection to achieve quality.
4. End the practice of awarding business on the basis of price
tag alone. Instead, minimize total cost by working with a single
supplier.
5. Improve constantly and forever every process for planning,
production, and service.
6. Institute training on the job.
7. Adopt and institute leadership.
8. Drive out fear.
9. Breakdown barriers between staff areas.
10. Eliminate slogans, exhortations, and targets for the work
force.
11. Eliminate numerical quotas for the work force and numerical
goals for management.
12. Remove barriers that rob people of pride of workmanship.
Eliminate the annual rating or merit system.
13. Institute a vigorous program of education and self improvement
for everyone.
14. Put everybody in the company to work to accomplish the transformation.
Dr. W. Edwards Deming
Back to top
Item #: SB-5
Price: $320.00
For more information on Sampling Boxes, call our experts toll free at:1-866-203-4309
|