Quality by Design (QbD) Space for Pharmaceuticals and Beyond...Quality by Design “QbD” Design...
Transcript of Quality by Design (QbD) Space for Pharmaceuticals and Beyond...Quality by Design “QbD” Design...
6/25/2013
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Quality by Design (QbD) Space for Pharmaceuticals and Beyond
*Presentation is posted at www.statease.com/webinar.html
There are 250+ attendees today! To avoid disrupting the Voice over Internet Protocol (VoIP) system, I will mute all. Please use Questions feature on GotoWebinar. Trygve will answer selected questions. Feel free to
By Wayne F. Adams, MS, Applied Stats.Stat-Ease, Inc., Minneapolis, MN
email questions to [email protected] which we will answer off-line. -- Wayne
1
Quality by Design It’s Not Just For Pharmaceuticals
*Presentation is posted at www.statease.com/webinar.html
There are 250+ attendees today! To avoid disrupting the Voice over Internet Protocol (VoIP) system, I will mute all. Please use Questions feature on GotoWebinar. Trygve will answer selected questions. Feel free to
By Wayne F. Adams, MS, Applied Stats.Stat-Ease, Inc., Minneapolis, MN
email questions to [email protected] which we will answer off-line. -- Wayne
6/25/2013
Copyright © 2013 Stat-Ease, Inc. Do not copy or redistribute in any form. 2
Getting Started: Stat-Ease Resources
New to Design of Experiments?
Take advantage of all the free resources available to you!g y
On the statease.com website:
• Beginner resources: http://www.statease.com/beginner.html
• Webinars: http://www.statease.com/webinar.html
Articles: http://www statease com/articles html• Articles: http://www.statease.com/articles.html
• Software Tutorials: http://www.statease.com/dx8_man.html
3June 2013 Webinar
Getting Started: Other Resources
New to Design of Experiments?
Take advantage of all the free resources available to you!g y
LinkedIn Groups:
• The Design of Experiment (DOE) Group – great place to post general questions about DOE’s
• ASQ Statistics Division – more general statistics and DOEQ g
• The Stat-Ease Professional Network – friends and clients of Stat-Ease
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Agenda Transition
Quality by Design – QbD Wh t i QbD What is QbD
(FDA references) Finding the design space with DOE
(tableting process)
Proving the control space (extrusion-spheronization)
5June 2013 Webinar
Quality by DesignFDA View on QbD1
Quality by Design is:
Scientific, risk-based, holistic and proactive approach toScientific, risk based, holistic and proactive approach to product development
Deliberate design effort from product conception through commercialization
Full understanding of how product attributes and process relate to product performance
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Quality by DesignFDA View on QbD2
QbD involves the following key elements:
Target the product profile.g p p
Determine critical quality attributes (CQAs).
Link raw material attributes, formulation and process parameters to CQAs and perform risk assessment.
Develop a design space.
Design and implement a control strategy.g p gy
Manage product life cycle, including continual improvement.
7June 2013 Webinar
Develop a Design SpaceStatistically Designed Experiments
1. First-principles approach Combine experimental data and mechanistic knowledge to
model and predict performancemodel and predict performance.
2. Statistically designed experiments (DOEs) Efficient method for determining impact of
multiple parameters and their interactions.
3. Scale-up correlations A semi-empirical approach to translate operating conditions
between different scales or pieces of equipmentbetween different scales or pieces of equipment.
4. Combinations of the above
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Quality by Design “QbD”Design Space Determination
1. A region where quality product is produced.
2. Includes product formulation and/or process parameters.
3. Arrived at by iterative application of risk assessment and experimental design to knowledge space.
4. Includes evaluation of scale and equipment.
ICH guidelines Q8 (on Pharmaceutical Development), Q9 (on Quality Risk Management), and Q10 (on Pharmaceutical Quality System) provide some assistance for manufacturers to implement Quality by Design into their own operations.
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Design Space DeterminationQuality by Design
FDA defines design space in its Guidance for Industry Q8: Pharmaceutical Development, as:
“The multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality. Working within the design space is not considered as a change. Movement out of the design space is considered to be a change and would normally initiate a regulatory post approval change process.
Design space is proposed by the applicant and is subject to regulatory assessment and approval.”
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Quality by DesignVerification of Specifications
Confirmation:
Simple confirmation
KnownFactors
UnknownFactors
Screening
One or several runs at optimal conditions compared to prediction from the “Confirmation” node.
Verification (QbD)Size design for tolerance intervals and use them to yes
Factor effectsand interactions
R
Curvature?
Screening
no
Trivialmany
Vital fewCharacterization
Optimizationback off from specifications. Response
SurfaceMethods
Confirm? Backup
Celebrate!
no
yes
Optimization
Confirmation
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Using DOE with Tolerance Intervals to Verify Specifications
Objective:
Define an operating window in process factor space where we have 95% confidence that 99% of the population meet (or exceed) specifications.
Tools:
Use empirical DOE to model the responses as functions of the process factors.
Use a tolerance interval to “back off” (provide a buffer) fromUse a tolerance interval to back off (provide a buffer) from the specifications.
Size the DOE for required half-width of tolerance interval.
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Agenda Transition
Quality by Design – QbD Wh t i QbD What is QbD
(FDA references)
Finding the design space with DOE(tableting process)
Proving the control space (extrusion-spheronization)
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Illustrative ExampleTableting Process
This case study illustrates how DOE and tolerance intervals can be used to set an operating window where specifications are
i t tl tconsistently met.
An optimal design is run on two process parameters (granulation time and lubrification time) in a tableting process.
Three responses (dissolution, friability and hardness) are measured.
The specifications are:The specifications are:
• Dissolution ≥ 75%
• Friability ≤ 0.5%
• Hardness ≥ 10 kP
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Initial Operating WindowSpecifications as Bounds
y1 = Dissolution %8.00
Specifications on Graphical Overlay
(specification ≥ 75%)
y2 = Friability %(specification ≤ 0.5%)
y3 = Hardness kP(specification ≥ 10 kP) 4.00
5.00
6.00
7.00
B: L
ub
rific
atio
n
Dissolution: 75.00
Friability: 0.50
3.00 4.00 5.00 6.00 7.00
2.00
3.00
A: Granulation
Hardness: 10.00
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Uncertainty is a BIG ProblemSpecifications as Bounds
If the tableting process is operated on a boundary, then 50% of tablets
d d f ll t id thproduced fall outside the specification.
Specification
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Gaining confidence that individuals are within specifications.
If we want more confidence that individual units are within specifications:
Then we should back off using a tolerance interval rather than a confidence interval.
Specify the confidence level; e.g. 95%.
Specify the portion of the population to be within specifications; e.g. 99%.
Note:Note:
A confidence interval pads our design space to give us confidence that the process mean is within boundaries.
A tolerance interval gives us confidence that a stated proportion of the population is within specifications.
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Tolerance IntervalDefinition
Tolerance Interval: An interval that covers a fixed proportion of outcomes from the population with a pre-determined confidence level for estimating the population mean andconfidence level for estimating the population mean and standard deviation.
( ) ( )
( )2 2
2
d i th h lf idth f th t l i t l
y k s P% of population y k s
TI y k s
TI y d
− ≤ ≤ +
= ±
= ±
d is the half width of the tolerance interval
y ULTILLTI
P% of population
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Interval CalculationsSingle Sample & Normal Distribution
Confidence Interval
sy t
± 2
Tolerance Interval
y k s±
df t α=0.05 k2 α=0.05, P=0.95
1 12.706 37.674
Note:
TI multipliers are larger than those for a CI; especially for small samples.
As the sample size increases:
• CIs shrink towards zero.
y tn
±
2y2 4.303 9.916
3 3.182 6.370
4 2.776 5.079
5 2.571 4.414
10 2.228 3.259
25 2.060 2.612
50 2.009 2.375
• TIs tend towards a fixed value: Z(s).
Larger sample sizes are needed for TIs than CIs.
100 1.984 2.232
∞ 1.960 1.960
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Tolerance IntervalCalculation for a DOE
ˆTI y
TI cal
d
culation for a DOE *
= ±
( ) ( )1T T 1 n ps t X X Pd
− − −+ Φ
Standarddeviation
Design Matrix“sample size”
Position inDOE space
Proportionof population
Confidence
0
0
TI y d
d fn(s, X, x , P, )
= ±= α
( ) ( )( )
( ) ( ) ( )
,df 0 0 2
,df
s t x X X x Pn p,1
d
d
s t TI multiplier
α
α
+ Φχ − − α
=
=
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TI Interval MultipliersSingle Sample versus Two-Factor DOE
Comparison:
single sample k2(α= 0.05, P=99%)df k2 α=0.05, P=0.99 (t)(TIM*)
10 4 277 5 013versus
(tα=0.05,df)(TI multiplierα= 0.05, P=99%)
Note: The tolerance intervals that cover the design volume are wider than those at a single point in space.
10 4.277 5.013
11 4.150 4.860
12 4.044 4.739
13 3.955 4.636
14 3.878 4.532
15 3.812 4.460
20 3.577 4.155
25 3 432 3 966
* Basis is average TI multiplier for a two-factor unconstrained IV optimal design for a quadratic model with 6+ model points, 5 lack of fit points and 5 replicates.
25 3.432 3.966
30 3.344 3.826
50 3.121 3.518
100 2.933 3.224
*TIM = TI multiplier
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Interval Multipliers for “s”TI DOE, TI sample and CI sample
t*TIM
KK2
t*(1/sqrt(n))
start at 10 df
degrees of freedom
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Back off from SpecificationOne-Sided tolerance interval (TI)
One-sided TI calculation for DOE
0 0
d is the off set for the tolerance interval
One-sided TI calculation for DOE
ˆ ˆTI y d or TI y d= + = −
TI Specificationnew boundary
d
23June 2013 Webinar
Picking a TI Off-SetThe Lower bound for “d”
A tolerance interval that covers the design volume is approximately 20% wider thanapproximately 20% wider than that at a single point in space.
Therefore, d must be greater than (1.2)(K1)(s):
d > (1.2)(K1(α=5%, P=99%, n=20))(s)
need to guess “n”
d (1 2)(3 295)( )
TI Specificationnew boundary
dd > (1.2)(3.295)(s)
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RSM DOE Process (1 of 2)
Tableting Process
1. Identify opportunity and define objective.Define an operating window in process factor space where we have 95% confidence that 99% of the population meets (or exceeds)95% confidence that 99% of the population meets (or exceeds) specifications.
2. State objective in terms of measurable responses.
a. Define the precision that is required for each response.Tolerance interval (α=0.05, P=99%) half-width (d):dissolution d = 9, friability d = 0.3, hardness d = 0.7
b. Estimate experimental error (σ) for each response.b. Estimate experimental error (σ) for each response.dissolution s = 2, friability s = 0.03, hardness s = 0.14
c. Use fraction of design space (FDS) to quantify precision.
25June 2013 Webinar
RSM DOE Process (2 of 2)
Tableting Process
3. Select the input factors and ranges to study.(Consider both your region of interest and region of operability.)
A = Granulation time: 3 7 minutesA = Granulation time: 3 – 7 minutesB = Lubrification time: 2 – 8 minutes
7 ≤ total mixing time ≤ 12
4. Choose a polynomial to estimate: quadratic
5. Select a design and:
Size design for precision needed
Examine the design layout to ensure all the factor combinations are Examine the design layout to ensure all the factor combinations are safe to run and are likely to result in meaningful information (no disasters).
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7
Two Component MixThe solid center line is the fitted model;is the expected value or mean
prediction.y
Fraction of Design Space Review
4
5
6
R1 y δ±
The curved dotted lines are the computer generated confidence limits, or the actual precision.
δ Is the half-width of the desired confidence interval, or the desired precision. It is used to create the outer straight lines.
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Note: The actual precision of the fitted value depends on where we are predicting.
3
0
1
0.25
0.75
0.5
0.5
0.75
0.25
1
0
Actual A
Actual B
Fraction of Design Space Review
Only 53% of the design space is precise enough to predict the mean within ± 0.64.
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Fraction of Design Space Review
53% of the design space h h d i d i i
7
Two Component Mix
53%has the desired precision, i.e. is inside the solid straight (red) lines.
4
5
6
R1 y δ±
53%
29
3
0
1
0.25
0.75
0.5
0.5
0.75
0.25
1
0
Actual A
Actual B
Whitcomb & Oehlert, “Sizing Mixture (RSM) Designs for Adequate Precision via Fraction of Design Space (FDS)”, htt // t t / bi /11 07 i i i (RSM) df
For More Details on Sizing DOEsfrom our past webinars
Sizing Mixture (RSM) Designsfor Adequate Precision via
Fraction of Design Space (FDS)
http://www.statease.com/webinars/11-07_sizing_mix(RSM).pdf
30
Pat WhitcombStat-Ease, Inc.612.746.2036
Gary W. OehlertSchool of Statistics
University of Minnesota612.625.1557
6/25/2013
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DOE with Tolerance IntervalsSizing for Precision Requirements
Define the precision required as the half-width of a Tolerance Interval that contains 99% of the population with 95% confidence:Interval that contains 99% of the population with 95% confidence:
Response Desired d sLower bound
on d*d/s
dissolution 9.0 2.00 7.9 4.5
friability 0.2 0.03 0.12 6.7
hardness 0.7 0.14 0.55 5
Size the DOE to the smallest (d/s) ratio.
*(1.2)(3.3)s is a lower bound on d. Since the desired d is higher thanthe lower bound on d, we can achieve a precise enough design
31June 2013 Webinar
FDS Graph
Sizing for Precision RequirementsDOE Sizing (page 1 of 3)
The default design has 16 runs (6 model, 5 lack of fit, 5 replicates) FDS = 0%
TI M
ultip
lier
2.000
3.000
4.000
d = 9s = 2a = 0.05P= 0 99
Design too small!
Ti M
ulti
plie
r
Fraction of Design Space
0.00 0.20 0.40 0.60 0.80 1.00
0.000
1.000
P 0.99
Fraction of Design Space
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FDS Graph
Sizing for Precision RequirementsDOE Sizing (page 3 of 3)
23 runs (13 model, 5 lack of fit, 5 replicates) FDS = 93%
TI M
ultip
lier
2.000
3.000
4.000
d = 9s = 2a = 0.05P= 0 99
Much better!
Ti M
ulti
plie
r
Fraction of Design Space
0.00 0.20 0.40 0.60 0.80 1.00
0.000
1.000P 0.99
Fraction of Design Space
33June 2013 Webinar
Sizing for Precision RequirementsDOE Sizing (page 2 of 3)
Re-build the design with increase the number of model points with 7 additional points to request 13 model points.
(13 model, 5 lack of fit, 5 replicates) 23 total runs
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Tableting ProcessResults
Analyze responses, aim for:
Dissolution ≥ 75%
Friability ≤ 0 5%
5.00
6.00
7.00
8.00Friability
ubri
ficat
ion
0.500
0.600
0.800
2 3
2 2
5.00
6.00
7.00
8.00Dissolution
ubri
ficat
ion
90.02 3
2 2
5.00
6.00
7.00
8.00Hardness
ubri
ficat
ion 12.00
13.00
2 3
2 2
Friability ≤ 0.5%
Hardness ≥ 10 kP
3.00 4.00 5.00 6.00 7.00
2.00
3.00
4.00
A: Granulation
B: L
u
3 3
3
3.00 4.00 5.00 6.00 7.00
2.00
3.00
4.00
A: Granulation
B: L
u
75.0
80.0
3 3
3
3.00 4.00 5.00 6.00 7.00
2.00
3.00
4.00
A: Granulation
B: L
u
10.00
11.00
3 3
3
35June 2013 Webinar
Final Operating WindowTolerance Intervals as Bounds
Set Graphical Optimization intervals and criteriafor each responsefor each response.
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Final Operating WindowTolerance Intervals as Bounds
y1 = Dissolution %8.00
Tolerance Intervals (α = 5%, P = 99%)
(specification ≥ 75%)
y2 = Friability %(specification ≤ 0.5%)
y3 = Hardness kP(specification ≥ 10 kP) 4.00
5.00
6.00
7.00
B: L
ub
rific
atio
n
Dissolution: 75.00
Dissolution TI: 75.00
Friability: 0.50
Friability TI: 0.50
3.00 4.00 5.00 6.00 7.00
2.00
3.00
A: Granulation
Hardness: 10.00
Hardness TI: 10.00
37June 2013 Webinar
7.00
8.00
Knowledge Space
Design Space
Quality by Design “QbD”Design Space Determination
4.00
5.00
6.00
Design Space
Control Space
3.00 4.00 5.00 6.00 7.00
2.00
3.00
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Agenda Transition
Quality by Design – QbD Wh t i QbD What is QbD
(FDA references)
Finding the design space with DOE(tableting process)
Proving the control space (extrusion-spheronization)
39June 2013 Webinar
QbD – New vs Existing Process
Implementation of DOE as a QbD tool depends on your current state of knowledge about the process:
New Process Optimization
Use RSM to simultaneously model the influencing factors and focus in on where to operate.
Use Tolerance Intervals to define the design space.
Existing Process
Design space is assumed to be known from pre existing Design space is assumed to be known from pre-existing production data.
Use factorial DOE with Tolerance Intervals to verify design space, that is, demonstrate that no large effects will occur.
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Extrusion-SpheronizationGeneral Process Background
The extrusion-spheronizationi l d i thprocess is commonly used in the
pharmaceutical industry to make uniformly sized spheroids.
It is especially useful for making dense granules for controlled-release solid dosage oral forms.
41June 2013 Webinar
Extrusion-SpheronizationQbD Background Info
Previous study of this process showed that four factors are the key drivers of sphere size. Based on experience we believe that
ithi th i th d ll t ithwithin the ranges given the process produces pellets with a mean size of 750 µm and within specifications; 700 to 800 µm.
Name Units Low High
Kneading time sec 200 300
Extruder speed rpm 60 80
Spheronizer time sec 700 800
Gather data to submit for QbD design space.
Spheronizer time sec 700 800
Spheronizer speed rpm 800 1000
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Extrusion-SpheronizationBuild the Design (page 1 of 3)
1. Build a four factor full factorial design:
Add 4 center points
43June 2013 Webinar
Extrusion-SpheronizationBuild the Design (page 2 of 3)
2. Enter the factor information:
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Extrusion-SpheronizationBuild the Design (page 3 of 3)
3. Enter the response name and units:
Leave the signal and noise blank,
ill i th d i f t l i t l i FDSwe will size the design for tolerance intervals via FDS.
45June 2013 Webinar
Extrusion-SpheronizationSize the Design (page 1 of 2)
1. Go to Evaluation and change the model order to “Mean”:
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Extrusion-SpheronizationSize the Design (page 2 of 2)
2. Go to the FDS graph “Tolerance Interval” and enter “d = 50” and “s = 14”:
The design is not precise enough: the black line (the capability of the design) is above the blue line d = 50(what is required by d and s).s = 14
a = 0.05P= 0.99
47June 2013 Webinar
Rebuild the design: “Yes” to “Use previous design info?”:
Extrusion-SpheronizationAugment the Design
2 Replicates, 2 Blocks, 3 Center points
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Extrusion-SpheronizationCheck Precision
Check precision of augmented design:
The design is precise enough: the black line (the capability of the design) is below the blue line (what is required by d and s).
d = 50s = 14a = 0.05P= 0.99
49June 2013 Webinar
Extrusion-SpheronizationQbD Illustration #1: Mean Model
Evaluate capability relative to the pellet size specifications: 700 to 800 µm.
Two responses are provided.
Response 1 shows the results if the process is stable over the range tested.
Response 2 shows the results if there are small effects.
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Extrusion-SpheronizationQbD Illustration #1: Mean Model
Design-Expert® SoftwareFactor Coding: ActualPellet size
CI BandsTI BandsDesign Points
820Warning! Factor not in model.
One Factor
Design Points
X1 = A: Kneading time
Actual FactorsB: Extruder speed = 70.00C: Spheronizer time = 750.00D: Spheronizer speed = 900.00
Pel
let s
ize
720
740
760
780
800
200.00 225.00 250.00 275.00 300.00
A: Kneading time
700
51June 2013 Webinar
Extrusion-SpheronizationQbD Illustration #2: Linear Model
820 820
linea
r ef
fect
s
700
720
740
760
780
800
linea
r ef
fect
s
700
720
740
760
780
800
200.00 225.00 250.00 275.00 300.00
A: Kneading time
680
700.00 725.00 750.00 775.00 800.00
C: Spheronizer time
680
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Extrusion-SpheronizationQbD Illustration #2: Linear Model
53June 2013 Webinar
Extrusion-SpheronizationQbD Illustration #2: Linear Model
Design-Expert® SoftwareFactor Coding: ActualOverlay Plot
linear effectsTI Low
800.00Overlay Plot
TI Low TI High
Design Points
X1 = A: Kneading timeX2 = C: Spheronizer time
Actual FactorsB: Extruder speed = 70.00D: Spheronizer speed = 900.00
725.00
750.00
775.00
C:
Sp
he
ron
ize
r tim
e
linear effects TI: 700.000
linear effects TI: 800.000
6
200.00 225.00 250.00 275.00 300.00
700.00
A: Kneading time
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Agenda Transition
Quality by Design – QbD Wh t i QbD What is QbD
(FDA references)
Finding the design space (tableting process)
Proving the control space (extrusion-spheronization)
S mmar Summary
55June 2013 Webinar
Verification for SpecificationsSummary
1. Size your DOE appropriately for its propose: Functional design – size via confidence intervals.
A confidence interval pads our design space to give us confidence that the process mean is within boundaries.
Verify specifications – size via tolerance intervals.A tolerance interval give us confidence that a stated portion of the population is within specifications.
2. TI multipliers are larger than those for a CI. As the sample size increases: As the sample size increases:
• CIs shrink towards zero.• TIs tend towards a fixed value.
3. Tolerance intervals require a large design (sample size).
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Quality by DesignDesign Space Determination
Summary:
Design space determination is a key aspect of QbD “Quality by Design”.
Design space is the multidimensional combination and interaction of input variables that have been demonstrated to provide assurance of quality.
DOE is a means to determine the design space:• Scope out initial formulation and/or process design.• CharacterizationCharacterization• RSM and numeric optimization• Determine design space (graphic optimization)• Verification
57June 2013 Webinar
QbD – New vs Existing Process
Implementation of DOE as a QbD tool depends on your current state of knowledge about the process:
New Process
Use DOE to simultaneously gain knowledge about the influencing factors and interactions, and learn where to operate.
Use Tolerance Intervals to define the design space.
Existing Process
Design space is assumed to be known Design space is assumed to be known. (pre-existing production data)
Use DOE with Tolerance Intervals to verify design space. (show no large effects present).
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ReferencesFDS, and TI
1. Alyaa R. Zahran, Christine M. Anderson-Cook and Raymond H. Myers, “Fraction of Design Space to Assess Prediction”, Journal of Quality Technology, Vol. 35, No. 4, October 2003.
2. Heidi B. Goldfarb, Christine M. Anderson-Cook, Connie M. Borror and Douglas C. Montgomery, “Fraction of Design Space plots for Assessing Mixture and Mixture-Process Designs”, Journal of Quality Technology, Vol. 36, No. 2, October 2004.
3. Steven DE Gryze, Ivan Langhans and Martina Vandebroek, “Using the Intervals for Prediction: A Tutorial on Tolerance Intervals for Ordinary Least-Squares Regression”, Chemometrics and Intelligent Laboratory Systems, 87 (2007) 147 – 154.
4. Gerald J. Hahn and William Q. Meeker, Statistical Intervals; A Guide for Practitioners, (1991) John Wiley and Sons Inc(1991) John Wiley and Sons, Inc,
5. Gary Oehlert and Patrick Whitcomb (2001), Sizing Fixed Effects for Computing Power in Experimental Designs, Quality and Reliability Engineering International, July 27, 2001.
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If we were unable to answer your questions l d th t bi @ t tplease send them to [email protected].
We will reply as soon as possible.
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Half-Normal Plot
Select signif icant terms - see Tips
30
50
70
80
90
95
99
Hal
f-N
orm
al %
Pro
babi
lity
g p
0.00 3.34 6.68 10.02 13.36
01020
|Standardized Ef f ect|
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Adjusted UnadjustedModel Model
F-value p-value F-value p-value
Model
Curvature 0.069 0.7943
Lack of Fit
0.33 0.9685 0.32 0.9723Fit
0.33 0.9685 0.32 0.9723
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