Analyze Flashcards
What question does the ANALYZE phase answer?
What causes the problem?
What methods are used to collect potential causes & develop hypotheses?
Fishbone, FEMA, 5-why, GEMBA
What are the parts of a Fishbone? Describe each part.
6 bones (‘M’s’) + Head
Machined
Measure
Man
Mother Nature
Method
Material
Head - Why don’t we fulfill CTC’s?
What are the steps of the fish-bone process?
Complete fishbone - brainstorm & cluster ideas (categories)
Rank ideas - Constant (c), Noise (n), Variables (x)
5-why
What is the result of fishbone & 5-why?
Hypothesis & potential causes
What is used to prioritize potential causes?
Tool 3
What is Tool 3?
Table to prioritize potential caused determined from fishbone, 5-why, etc.
What are the parts of Tool 3? What is the process for using it?
Table: Output measurements vs. potential causes
Prioritize each
- 9 High Impact
- 3 Med Impact
- 1 Low Impact
- 0 No Impact
Sum up each column.
Creating ranking based on sum
Handle the ‘verification’ process - this is the Process door & Data door.
Review results from process & data door.
Determine true root cause
What is GEMBA? What are the steps?
An opportunity to capture topics & concerns related to how effectively the process is performing. Purpose is to allow managers/leaders to observe the actual work process, engage with employees, gain knowledge about the work process, and explore opportunities for continuous improvement.
A concept that can be used in any part of the DMAIC cycle or anywhere that value is created.
1. Choose process.
2. Determine hypothesis.
3. Measurements & Data
4. Observations (often video taped)
5. Insights & conclusions.
Rules
1. Go & see
2. Ask why
3. Respect people
What are ways to ‘verify’ potential causes through process (process door)?
Process mapping
Value analysis
Time analysis
Capacity analysis
What are the ways to ‘verify’ potential causes through data (data door)?
Data Stratification
Hypothesis testing
Design of Experiment (DOE)
What are the different types of processing mapping?
Flow charts
Swimlanes
Spaghetti diagrams
Value stream diagrams
What are the different types of value analysis? Describe each type.
Value adding - customer pay
Non-value adding - waste
Value enabling - company pay
What is the tool used to identify waste in a process? Describe the tool.
TIM WOODS
Transport
Inventory
Motion
Waiting
Over Production
Over Processing
Defects
Skills
Describe the ‘Data Stratification.’
Find graphical evidence that a potential cause (hypothesis) may be valid by splitting the data into logical subcategories - what, when, how, where, who?
What are the calculations for the ‘Time Analysis’ verification step (process door)?
Determine process lead time (PLT).
Determine exit rate (ER).
Determine work in process (WIP)
Calculate Little’s Law (WIP/ER)
Calculate process cycle efficiency (PE).
What is Process Lead Time? What is its symbol? How is it calculated?
(Note: Little’s Law is a separate question)
PLT = sum of all process time
E.g waiting, processing, setup/change-over time, transportation, inspection, etc.
2 options
1. Measure
2. Little’s Law
What is the exit rate? How it is calculated? What is its symbol?
Exit rate calculates the number of pieces over time for that process.
ER = # pieces/time
Determined by the process step with the lowest capacity (aka the bottleneck)
What is WIP?
Work in Progress - material waiting to be finished in the process.
What is Little’s Law?
A way to calculate Process Lead Time (PLT).
PLT = WIP (item) / ER (item/time)
Concept - reduce either WIP or ER to improve process.
What is the Basic Principle of Hypothesis Testing?
Compare the confidence intervals of different data sets to see if there is a significant difference.
If you compare the confidence intervals of 2 different sets of data and the data sets overlap, what does that tell you? What if they do not overlap?
Overlap = no significant difference in the data sets
Gap = significant difference in the data sets
How is Process Cycle Efficiency calculated? What is its symbol?
PE = VA/PLT
VA = total processing time of all value-adding steps. To get this, evaluate the process steps using value analysis. Reflection of waste level.
What are the primary parts of Capacity Analysis (process door)?
Takt rate calculation
Takt time calculation
Understanding bottlenecks & constraints
What is Takt Rate? What is its symbol? How is it calculated?
TR = # units to be produced per customer need / available production time
What is Takt Time? What is its symbol? How is it calculated?
TT = Available production time / # units to be produced per customer need
True/False: If the Exit Rate is bigger than the Takt Rate, the process can satisfy customer demand.
True
True/False: If the Exit Rate is smaller than the Takt Rate, the customer demand can be fulfilled?
False
What is the difference between bottlenecks & contraints?
Bottleneck: slowest process step; there is always a bottleneck
Constraints: if the bottleneck prevents fulfilling customer demand
What are the different types of hypothesis options for hypothesis testing? What do the mean?
Ho - Null Hypothesis - no significant difference
HA - Alternative Hypothesis - significant difference
When selecting Ho or Ha during hypothesis testing, the decision can be accepted or rejected based on the p-value. How can one understand the risk of making an incorrect selection?
Alpha error: rejection of null hypothesis although it is correct; max accepted risk is 5%
Beta error: failure to reject the null hypothesis although it is wrong
What are the stratification factors for ‘Data Stratification’?
Who?
When?
Where?
What?
How?
What is the purpose of hypothesis testing (data door)?
To tell if we are right or wrong about our hypotheses. To check if the differences in our data are statistically significant.
Describe the 2 types of ‘First Leads for Hypotheses.’
Comparison Hypotheses - e.g. Kaitlyn shoots shorter than Matt.
The… The… Hypotheses - e.g. The higher the tension, the further the distance.
How can we describe the Null Hypothesis?
Ho = Null Hypothesis
Everything is equal (comparison hypotheses)
Everything is free of influence (the… the… hypotheses)
Everything is free of significance (regression model)
True/False: You can prove equality or freedom of the Null Hypothesis?
False. You cannot prove equality or freedom, so instead you prove the alternative, aka ‘Reject the Null Hypothesis.’
How can we describe the Alternative Hypothesis?
Ha = Alternative Hypothesis
It is not equal.
It is not free of influence.
It is not free of significance.
True/False: You can prove an alternative hypothesis not equal.
True. You can prove prove Ha. If Ha is valid, then Ho can be rejected.
In hypothesis testing, how would you describe the risk you are willing to take?
In statistics, accepted alpha-error is 5%, which is the max accepted risk to reject Ho wrongly.
What does it tell you if the p-value is smaller than the alpha-level?
Shows the actual risk of rejecting Ho wrongly.
Hypothesis Test Overview: What tests for the below?
Target Value (y) = discrete
Influencing Value (x) = discrete
1-proportion test
2-proportion test
chi^2 test
Hypothesis Test Overview: What tests for the below?
Target Value (y) = continuous
Influencing Value (x) = discrete
1-sample t-test
2-sample t-test
1-way ANOVA
2-way ANOVA
2-variances test –> F-test or Levine’s test
Test for equal variances –> Bartlett’s or Levine’s test
Hypothesis Test Overview: What tests for the below?
Target Value (y) = continuous
Influencing Value (x) = continuous
Correlation
Regression
Hypothesis Test Overview: What tests for the below?
Target Value (y) = discrete
Influencing Value (x) = continuous
Logistic Regression
What are the names of the 3 normality tests in Minitab?
Anderson-Darling
Ryan-Joiner
Kolmogorov-Smirnov
How do you deal with non-normality? (4 options)
- Get more samples.
- Data stratification.
- Remove special causes & document
- Take data like it is.
What are the prerequisites for the 1-way ANOVA hypothesis test?
Sigma^2(1) = Sigma^2(2) = Sigma^2(3)…
which is the Ho for Test for Equal Variances…
which means Bartlett’s test or Levine’s test
In hypothesis tests, what is ‘x’?
Influencing factor