CLINICAL CHEMISTRY – RMT 2024
LAB 6 – SIX SIGMA
Mr. Fritz A. Bucao, RMT
September 2022
SIX SIGMA
LEAN SIX SIGMA AND CONTROL CHART ANALYSIS
manufactured are measured in multiple billion. This one still,
the 0.27 will represent even 2,700 failures per million parts
manufactured. In that problem this is where your six sigma
comes in. There is an insurance that 99.999% of the yield or
success rate work as intended.
→ We have six standard deviations outward from the mean and
this reduces parts per million defects to only 3.4 DPMO
(defects per million opportunities). The 3.4 is just a more
acceptable number and might be one of the best that we can
offer.
NUMERICAL
DIFFERENCE
3 SIGMA
Deviation of more than
one-sixth part: (+/-)
1.66%
Represents deviation
of 2,700 per million
● Sigma is the 18th letter of greek alphabet
● English translation is the letter S
→ In the image above, the sigma is a lowercase sigma since the
uppercase sigma refers to mathematical sum.
→ This means Six standard deviations, your six sigma is a
problem solving methodology. It focuses more on six standard
deviation distance from your mean in both direction instead of
the usual 3 SD deviations.
6 SIGMA
Deviation of no more than one-twelfth
part: (+/-) 0.83%
Represents deviation of 3.4 per million
Accuracy of 99.99966%
Accuracy of 99.73%.
PRODUCTION
MANAGEMENT
Focus is on
manufacturing
process
the
More inclusive, extending to every
essential business process
EXAMPLES
135 wrong surgical
procedures performed
across Canada per
week
1 wrong surgical procedure performed
across Canada in 192 years
54,000 checks would
be lost each night by a
single large bank
Only 4 checks would be lost in 3
months by a large bank
Only 2 invoices would be sent out
incorrectly in 50 years by a similar
4,050 invoices would
be sent out incorrectly
each month by a
modest-sized
company
EXAMPLES:
● This is the graph of normal SD underscores, the statistical
assumptions of your six sigma model.
● So if you assume that your business process operates like a normal
distribution or this bell-shaped curve. There are certain
assumptions that can be made. The process performed within
about 3 SD, it means that from the process average and defining
the quality of the process using the upper and lower specification
limit then your six sigma process is one where the nearest
specification limit is at least six standard deviation away from the
average and the number of your standards deviation from the
average and the nearest limit is called as the sigma level.
● Sigma level equates yield percentage
● YIELD PERCENTAGE
→ other wise known as success rate
● Amazon process around 36.8 million orders, let's assume that each
order error costs the company with an average of 35 dollars. This
is a very conservative number considering that the cost may include
return shipping or the labor to answer customer or phone calls or
emails and labor & shipping to write a wrong order. It is seen in the
situation that even one sigma shift, 5 sigma to 6 sigma will enable
the company to save a high amount of money. Considering the
difference between your three hundred thousand and four thousand
dollars, that's how important and beneficial your 6 sigma to
business and other industries.
SIX SIGMA
● It is a methodology for continuous improvement.
● It is a methodology for creating products or processes that perform
at high standards.
● It is a set of statistical and other quality tools arranged in a unique
way.
● It is a way of knowing where you are and where you could be.
● It is a quality philosophy and management technique.
● Six sigma is a measure of quality that thrives near perfection
● NOT a metric-like percentage
● The common probability dictates that 99.73 of all outcomes will fall
within the 3 SD. Either above the mean or below the mean.
● For most purposes this is a fine system but there are few scenarios
in daily life or most professions where in your 99.73% certainty or
accuracy is not that acceptable. With modern manufacturing
techniques, the massive amount of material output means that
even the remaining 0.27 of your 99.73% of the whole is still a
significant number.
→ Example: In the manufacturing of the vehicles where in safety
is one of the primary concerns. The 0.27% defect rate is
literally a killer in this case. This will result into a functionally
massive number of defective parts even though the
percentage looks small and after all in an industry where parts
Clinical Chemistry 1, CDU – BSMT3
NOTE
Take note that six sigma is not a standard but using this method to
achieve standards in your institution. This is also not a certification,
but most of the time you will be certified or someone in your institution
needs to be certified in order for the six sigma to be implemented in
the company.
Page 1 of 6
SKALA SIX SIGMA
● based on the six-sigma table, six sigma process only 3.4 defects
for every one million time you run the process (nearly perfect)
● DPMO (Defects per Million Opportunities)
1σ (one sigma)
● Sigma Level: 1σ (one sigma)
→ process only 30.8% or yield success rate
● the higher your sigma levels, the less chance of failure of a process
which:
→ reduces waste and efficiencies
→ can directly impact the financial cost performance of the
company
● Sigma Process represents the capability of your company and its
processes to exceed / define criteria for acceptability
● Example:
→ In the laboratory, this could refer to your assay performance
or your turnaround time or even the number of your rejected
samples that the specimen transport or even relaying critical
values
● By lowering your defects:
→ the quality care is also improved
→ cost-savings are realized by eliminating waste such as
supplies and materials that we use for reruns and
unnecessary steps in the process and also the staff time
YIELD %
SIGMA
90.32
88.5
86.5
84.2
81.6
78.8
75.8
72.6
69.2
65.6
61.8
58
54
50
46
43
39
35
31
28
25
22
19
16
14
12
10
8
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2
1.9
1.8
1.7
1.6
1.5
1.4
1.32
1.22
1.11
1
0.92
0.83
0.73
0.62
0.51
0.42
0.33
0.22
0.09
DEFECTS PER MILLION
OPPORTUNITIES
96 800
115 000
135 000
158 000
184 000
212 000
242 000
274 000
308 000
344 000
382 000
420 000
460 000
500 000
540 000
570 000
610 000
650 000
690 000
720 000
750 000
780 000
810 000
840 000
860 000
880 000
900 000
920 000
CLIA 88 GUIDELINES
● Most proficiency testing requires 80% accuracy rate
→ which this translates to around 200,000 DPMO or 2.4 sigma
(nearest to 200k)
→ the requirement of CLIA for proficiency testing for six sigma
HISTORY OF SIX SIGMA
● started in the electronic manufacturing processes at Motorola
● discovered in USA, year 1980
● since then it has been applied as a process improvement
methodology across the range of industries (like your ID, healthcare
sales, finance and even in your military)
NOTE
The higher the sigma levels, the lesser chance of failure
SIX SIGMA
YIELD %
99.9997
99.9995
99.9992
99.999
99.998
99.997
99.996
99.993
99.99
99.985
99.977
99.967
99.952
99.932
99.904
99.865
99.814
99.745
99.654
99.534
99.379
99.181
98.93
98.61
98.22
97.73
97.13
96.41
95.54
94.52
93.32
91.92
YIELD TO SIGMA CONVERSION TABLE
DEFECTS PER MILLION
SIGMA
OPPORTUNITIES
6
3.4
5.92
5
5.81
8
5.76
10
5.61
20
5.51
30
5.44
40
5.31
70
5.22
100
5.12
150
5
230
4.91
330
4.8
480
4.7
680
4.6
960
4.5
1 350
4.4
1 860
4.3
2 550
4.2
3 460
4.1
4 660
4
6 210
3.9
8 190
3.8
10 700
3.7
13 900
3.6
17 800
3.5
22 700
3.4
28 700
3.3
35 900
3.2
44 600
3.1
54 800
3
66 800
2.9
80 800
Clinical Chemistry 1, CDU – BSMT3
● coined by Bill Smith, known as the “father of six sigma”
→ He worked first as an engineer in the motorola
● In 1987, Motorola officially launched its Six Sigma Program
→ they have saved approximately 17 billion dollars from 1986 to
2004
● In 2002 to 2003 the Green Belt Certification became the criterion
for promotion to management roles
● Six sigma is the division from an ideal level of operations in which
where each level of your sigma starting from one up to six allow for
fewer defects
● Value of SIX
→ for every millions of chances there are only 3.4 defects which
translates to 99.99966% success rate
NOTE
Every million = 3.4 defects = 99.99966% success rate
DEFINE, MEASURE, ANALYZE, IMPROVE, & CONTROL (DMAIC)
● DMAIC - most common way to implement six sigma (although there
are several different ways)
Page 2 of 6
PHASES OF DMAIC (DMAIC Methodology)
DEFINE
MEASURE
ANALYZE
IMPROVE
CONTROL
● describes the quality improvement issues
● phase where the team now collects the data to
measure the process
● they determine the difference between your
current process and your desired process
● where you search for the root causes of your
inefficiencies in the process
● where the team pilots process changes that
seek to remove and identify your root problems
● when the team continues to measure the
process and ensure that the changes are
maintained
● Third Root Cause: This also found out that technologists are
frequently interrupted by healthcare staff.
● That is why visitors in the hospital that stops and ask directions
at the specimen drop off window due to its proximity to a busy
elevator.
The team next develops strategies that address each of these
specific problems and need to pilot the changes using the improve
phase.
IMPROVE PHASE
● Once the changes are implemented, the team measures the
process again and finds that the number of mislabeled
specimens that occurred on its shift is 4.
→ This is an 80% reduction in the number of your mislabeled
aliquot.
→ That is why it exceeds the goals of 60% set by the project
charter.
● First: maintaining three working label printers for aliquot station.
● Second: For this example, this includes your stocking of liquid
tubes and caps at the beginning of each shift
● Third: Ensure that the maps are readily available at the elevator
CONCLUSION: DMAIC METHOD
● Once the changes are implemented, the team measures the
process again and finds that the number of mislabeled
specimens that occurred on its shift is 4.
● The way the aliquots are made did not change, instead
modifying the steps around the process was enough to improve
the outcome, the level set by the project charter.
APPLICATION OF DMAIC METHODOLOGY IN REAL LIFE
SCENARIO:
PROBLEM: There is a high rate of mislabeled aliquot liquid tubes.
DEFINE PHASE: Set the goal to reduce the number of your
mislabeled aliquot tubes when the specimens arrive within two
months
● In this phase, you set the goal that you need to reduce the
mislabeled aliquot tubes to 60%
● Example: the number of your mislabeled aliquot tubes when the
specimens arrive within two months
● By the end of your defined phase, both the project team and
your management team have validated the project charter
● Project Charter - states the overall process or the overall
purpose and the potential impact, the scope of the project and
its resources and its expectation and what will be delivered and
when will be delivered
MEASURE PHASE: Monitor the number of aliquot tubes made on
each shift and the number of mislabeled aliquot tubes
● Next, in the measure phase, you will map and assess the current
process
● Again, the problem is mislabeled aliquot tubes. In your measure
phase, the number of aliquot tubes made on each shift and the
number of mislabeled aliquot tubes would be monitored.
● Data collected would allow the team to calculate the current
percentage of mislabeled aliquot tubes that occurs on its shift
● In doing so, the team will also map:
→ how your aliquots are made
→ the number a specimen received
→ where labels are printed
→ where the aliquot tubes are stored
→ how many technologies are involved in the process
● In this laboratory, it is found out that there are three technologies
or med techs that are responsible for making aliquots and they
all share one common label printer
● you also identify that there are bags of empty aliquot tubes and
caps stored in the laboratory surplus room at the back of the
laboratory.
● It is also found out that 20 out of every 100 aliquot tubes are
mislabeled
● Therefore, the goal of the project using the DMAIC
methodology:
→ you need to reduce the number of mislabeled specimens
from 20 to 8 samples for every shift.
ANALYZE PHASE:
● This phase now identifies the root causes of the problem.
→ Using the Cause-Effect Data Analysis
● Looking at your data collected, the group identifies several
issues that most likely contribute toward the mislabeled aliquots.
● First Root Cause: The shared labeled printer between 3
technologists making aliquots that will create confusion about
which printed label belongs to which technologist.
● Second Root Cause: During high volume times, the
technologist frequently runs out of aliquot tubes caps
● You must retrieve bags from the empty tubes from the
classroom at the back of the laboratory.
● Now this results in samples accumulating at the aliquot station
and it causes the technologist to rush to keep up with the
demand.
Clinical Chemistry 1, CDU – BSMT3
ADDITIONAL INFORMATION
Other ways to implement 6 sigma:
DMADV (Define, Measure, Analyze, Design and Verify)
● used to develop a new process when DMAIC method has failed
to correct an error-filled process
(for the sake of this discussion we'll only use the DMAIC
methodology)
LEAN SIX SIGMA
● As we all know, the six sigma will reduce error.
● However, the lean’s function is used to remove a process that does
not bring value to the customer.
● We call this process that doesn’t bring value to the customer, a
waste.
● Lean will now remove the waste
● If six sigma will remove defects or errors, the lean is defined to
remove waste.
● A combined methodology that focuses on eliminating problems by
removing inefficiencies and waste.
● This will improve your working conditions and will ensure that
customer needs are better satisfied.
● The combination of these two ideas will provide a positive
synergistic impact on process and the quality improvement.
Goal of the LEAN
● Remove the waste
→ Muda (Japanese term for waste) - anything that does not add
value for the end customers
Goal of the SIX SIGMA
● To reduce variation or defects
● Advantages/Benefits:
→ increase again with success, profit
→ standardize and simplify the process
→ reduce errors
→ Employee development
→ Add values to the customers
Page 3 of 6
Six Sigma Methodology
Three Team Roles of Six Sigma
Black
 Dedicate 100% of their time to quality
Belt
improvement projects
 Proactively address process and quality
problems
Green
 Contribute 20% of their time to improvement
Belt
projects while delivering their normal job
function (board exam question)
Blue
 They are the project sponsors or they are the
Belt
mid-senior level sponsors who review the
project.
 Removes organizational barriers and encourage
the team members.
Purple
 Typically head the smaller scale improvement
Belt
projects
 Condenses it to 1 week only to improve more
focused and more limited processes
→
→
Full Six Sigma improvement projects take six to eight
months to complete
The sampler scale improvement projects are typically headed
by the Purple belts.
Applications of Six Sigma in the Laboratory
Levels of Six Sigma Training
White
 This level only demonstrates a basic or
Belt
introductory level of knowledge to the
fundamental concepts of the six sigma and all of
the staff in the laboratory will likely go to this
level–white belt training.
Yellow
 Indicates that you have learned the specifics of
Belt
how your six sigma works or how its disciplines
are applied to the workplace and where it is best
to concentrate your time as you learn the
process.
 You also prepare the staff to be the team
members of the Six sigma process.
Green
 Focuses on advanced analysis and resolution of
Belt
problems related to quality improvement
projects
 You lead and manage projects while also
providing support to the black belts
Gray
 This signifies that you are already an expert in
Belt
the six sigma philosophies and principles.
 Known as agents of change within the
organization
 They are the ones who lead the project teams,
usually on a full-time basis.
 They also monitored the yellow and green belts.
Black
 In this level of training, the staff are responsible
Belt
for training the gray belt in an organization or
laboratory.
 This designation is given to those who are
trained in many performance improvement
methodologies and have many years of
leadership,
project
management,
and
mentorship experience.
Blue
 The champion
Belt
 is usually given to a high-level executive, for the
division leaders or directors,
 they are responsible for the overall quality in the
organization.
 Oversee the entire process and are especially
important at the beginning of six sigma
implementation when changes are most likely to
 arise.
● Reduce errors in the pre-analytical, analytical, and post-analytical
phases of testing
● Improve Safety
● Reduce turnaround times (TATs)
● Improve accuracy of analytical tests
● Optimize quality control (QC) rules
Two Ways to Determine Sigma
1.
DPMO (Defects per million opportunities)
→
Short term typically usued
→
Most common method
 Count defects
 Converts to DPMO
 Look up in Sigma table
→
DPMO - a ratio of the number of defects (flaws) in 1 million
opportunities when an item can contain more than one defect.
Example 1: A unit has 5 parts, and in each part, there are 3
opportunities of defects. What is the DPMO if 10 units have 2
defects.
2 - total no. of defects
5 - sample size (multiply 5 parts in every 3 opportunities)
3 - number of defect opportunities per unit in the sample
Substitute:
DPMO =
2
[(5)(3)] [10]
(1,000,000)
DPMO = (0.01333333333) (1,000,000)
Clinical Chemistry 1, CDU – BSMT3
Page 4 of 6
Example 2:
DPMO = 13, 333.33
Sigma = 3.7
3 Glucose Methods: Are they acceptable?
Glucose Total Allowable Error = 10%
from the conversion table above
Example 2: A form contains 15 fields of information. If 10 forms are
sampled and 26 defects are found in the sample, what is the
DPMO?
26 - total no. of defects
10 - sample size (multiply 5 parts in every 3 opportunities)
15 - number of defect opportunities per unit in the sample
Substitute:
Total
Precision
(CV)
Method A
2.3
Method B
1.9
Method C
1.9
2.1
3.4
4.2
3.05
0
5.26
Bias
Sigma Metric
(answers)
Method A:
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
=
10−2.1
= 3.4
DPMO = 173,333.33
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
=
10−4.2
= 3.05
Sigma = 2.4
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
=
10−0
DPMO =
2.
26
[(10)(15)] [10]
(1,000,000)
Sigma-Metric Equation
→
Measures variation
 Method Decision Chart
→
→
𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚−𝑙𝑙𝑙𝑙𝑙𝑙 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚
𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚
𝐶𝐶𝐶𝐶
𝐶𝐶𝐶𝐶
Method Decision Chart
Formula:
Sigma metric equation for Analytical Process Performance
BIAS =
𝐶𝐶𝐶𝐶
2.3
1.9
1.9
= 5.26
● For your method decision chart, your Y axis is where you plot for
the percent bias to reflect and observe the inaccuracies.
● As for the X axis, you plot the percent coefficient variation to reflect
the observed imprecision.
● You just have to scale
x 100
TEa - Total Error Allowable
Bias/CV/Coefficient of Variation
mostly represent systematic and random error
obtained from the external quality assurance record
systematic difference between the results obtained
by the laboratory and results obtained from the
group mean
Example 1:
3 levels of Cholesterol study, Clin Chem July 2014
•
CLIA PT Criterion for acceptability = 10%
Total
Precision
(CV)
1.0%
0.9%
1.0%
Bias
Sigma Metric
(answers)
3.0%
7.0
2.5%
8.3
2.3%
7.7
Given: (1st column)
10 - TEa (CLIA PT criterion for acceptability)
3 - Bias
1 - CV (number above 3.0%)
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
𝐶𝐶𝐶𝐶
=
10−3
1
= 7.0
→
→
→
Given: (2nd column)
10 - TEa (CLIA PT criterion for acceptability)
2.5 - Bias
0.9 - CV (number above 3.0%)
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
𝐶𝐶𝐶𝐶
=
10−2.5
0.9
You have to put 0 and the TEa on the Y axis
For the X axis you have to start with 0 and afterwards the half
of your TEa
So, we have a TEa of 10 which is divided by two so the result
would be 5
= 8.3
Given: (3rd column)
10 - TEa (CLIA PT criterion for acceptability)
2.3 - Bias
1.0 - CV (number above 3.0%)
Sigma metric =
𝑇𝑇𝑇𝑇𝑇𝑇−𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵
𝐶𝐶𝐶𝐶
=
10−2.3
1.0
Clinical Chemistry 1, CDU – BSMT3
= 7.7
→
Always scale the Y axis from 0 to Tea
Page 5 of 6
→
For the criterion, we have to divide Tea to the sigma level
(e.g. Tea is 10)
 10 divided by 2 = 5
 10 divided by 3 = 3.3
 10 divided by 4 = 2.5
 10 divided by 5 = 2.0
 10 divided by 6 = 1.67
→
→
A graph of an imprecision chart
The graph of the said example
→
→
If it is Excellent, Good, Marginal, Poor, and Unacceptable
Again, on the X-axis is the CV and on the Y-axis is the
Percent Bias
Application of Sigma Method:
→
→
→
Method A = Marginal
Method B = Marginal
Method C = Excellent
Therefore, among the three Glucose Assay Performance Method
Decision Chart, Method C is more acceptable.
Clinical Chemistry 1, CDU – BSMT3
Page 6 of 6