Lean Six Sigma Flashcards
Green Belt Baby!
7 Wastes
TIMWOODS Transport access Inventory Motion Waiting Over Production Over Processing Defects Skills
Difference between Lean and Six Sigma
Lean
- minimizes resources use, reduction cycle time,
- reduced muda, mura and poor economics
Six Sigma
- minimizes variation
- reduces undesired variation
- Doesn’t look at wastage
- Doesn’t look at non-standard processes
- Data driven/repitition
TOC
Theory of Constraints
reduced bottlenecks
Six Sigma
a set of management techniques intended to improve business processes by reducing the probability that an error or defect will occur.
4.5 Sigma variation + 1.5 Sigma process walk
DPMO
Defects per million opportunities
= (No. of defects in sample)/(No. opportunities for defects in sample) * 1000 000
PPM
Parts Per Million
=(Total no. of defects in a sample)/ (sample size) * 1000000
DPU
Defects per unit
=(Total number of defects per sample)/(sample size)
Sources of variation
Common Cause: - Random -Systemic issues *Can be caused by inputs/machinery/environmental/change/people Can be predicted
Special Cause -Non-random -Can be identified *Can be caused by something in the system (environmental), usually confined to individuals Can be eliminated
Defect level of a company operating at 6 sigma?
3.4PPM
What is a Six Sigma Green Belt
Is able to use tools to analyse results within the context of process improvement projects.
SIPOC
Suppliers, Inputs, Process, Outputs, Customers
Backwards: COPIS
What shape is used to represent a decision in a process flowchart
Diamond
What does R&R stand for in gage R&R. What is the tool used for?
DMAIC-> measure tool
Repeatability -what variation do I introduce each time I repeat?
Reproducability - When another person does the same measurement.
Statistical tool that measures amount of variation in a measurement system arising from the measurement device and the people taking the measurements.
Which of the following basic quality tools can be used to identify the root cause of a problem? A. Fishbone B. Process Flow C. Pareto Chart D. Run Chart E. Histogram
A. Fishbone
What is Takt time - Is it a PUSH or PULL system?
- rate at which the finished product needs to be complete to meet the customer demand
= net available time/ customer demand
Define Kaizen
Continuous improvement
Define Kaikaku
Radical Change
What are some of the limitations of SixSigma
Only for repetitive/ standard processes
Vary Formulaic/ can hinder innovation
Law of Diminishing Returns
For normal distribution, two standard deviations on each side of the mean would include what percentage of the total population?
A. 95%
B. 68%
C. 99.73%
A. 95%
Explain the purpose of the project charter
Document that formally authorizes a project Defines scope Define roles Defines success Used to avoid Scope Creep
What is SMART
Specific Measurable Attainable Realistic Time Bound
Give three examples of KPI’s
Leadtime
Defects
Return Rates
How would you determine CTQ?
C- Ctitical
T- to
Q - Quality
It is the voice of the customer (requirement) converted to a measurable set of indicators (with a set of boundaries)
Which tool combines customer requirements, design considerations and design alternatives in a three dimensional matrix to which you can assign weighted scores based on market research information collected
House of Quality or Quality function Deployment (QFD)
What is PDCA
Plan Do Check Act (Deming proposed Cycle)
What is FMEA, when and how is it used?
Failure Mode Effect Analysis
DMAIC -> Analyze tool
Accesses Risk by three factors:
Severity
Occurrence
Detection
Warranty claims are classified in which of the following cost of quality groups: A. Internal Failure B. External Failure C. Appraisal D. Prevention
B. External Failure
Errors in the entry of billing numbers into a computer system are on average 4%. Given this process is capable, what should the sample size for the control study be?
On average you should see 2 attributes within your sample.
Therefore:
2*100/4 = 50 -> Sample size is 50
When is a process capable?
When it can meet customer specifications
More specifically: When the upper/lower +/-3 sigma control limits (UCL/LCL) lie withing the Upper and Lower Customer Specification Limits (USL/LSL)
(Look at the page Matthius gave us labelled ‘SPC’ for example)
When is a process in control?
When it only exhibits random variation
What does DMAIC stand for?
Define Measure Analyse Improve Control
7 tools of Quality
- Process Flow
- Check Sheet
- Run Chart
- Histogram
- Pareto Analysis
- Scatter Diagram
- Cause and Effect Diagram
What are the 6M’s
For analyzing performance/cause and effect:
DMAIC -> Analyze tool:
1, Man (people)
- Methods (process)
- Machines (technology)
- Materials
- Measurements (inspections)
- Milieu/ Mother nature (environment)
Deming proposed the following (3)
- Believed that natural variation is inherent in all processes
- Viewed quality through management as a system
- Suggested that management is responsible for 85% of quality problems (shop floor employees only 15%)
Process flow -> Symbol for ‘waiting’
Upside down triangle
Process flow -> Symbol for ‘start/stop’
circle
Process flow -> Symbol for ‘task’
square/rectangle
Costs of quality
DMAIC -> Analyze tool:
- Prevention
- Appraisal
- Internal Failure
- External Failure
5S (6S)
DMAIC -> Improve tool:
```
Sort
Set in Order
Shine
Standardize
Sustain
6: Safety
~~~
CANDO
DMAIC -> Improve tool:
Clean Arrange Neatness Discipline Ongoing Improvement
SMED
DMAIC-> Improve tool:
Single Minute Exchange of Dyes
Where does SPC come into DMAIC?
Control
Current Reality Tree
DMAIC-> Analyze tool:
Root Cause Analysis tool
*Begins with a list of undesirable effects
*Depicts Cause and Effect reasoning
(It looks like a tree - the example of the car in the pool was used in class)
Example of attribute data
Count items such as number of defects
Uses p-chart only
Example of variable data
Measurement of particular characteristic, such as width
Uses X-bar (averages) & R-chart (ranges)
Pareto Analysis
DMAIC -> Analyse
Statistical technique that is used to find a limited number of tasks that produce a significant overall effect.
Pareto principle: 80/20 rule
20% of the work can generate 80% of the benefit
Define stage of DMAIC (name 5)
Project Charter stakeholder analysis voice of customers brainstorming tools affinity diagram Kaizen/Kaikaku SIPOC CTQ KANO KPI's SMART
Measure tools of DMAIC (name 5)
Basic Quality tools Hard and Soft Savings gauge R&R DPMO/DPU/PPM Urgent/Important matrix Breakthrough equation Process Analysis Takt time Capability Analysis
Analyze tools of DMAIC (name 5)
Value stream mapping Root Cause Analysis (Current Reality Tree, 5 Why's, Fishbone) Cost of Quality Spagetti Diagram Business Impact Analysis FMEA - Failure Mode & Effect Analysis Seven deadly wastes Design of experiments Pareto Analysis (80/20 rule) Affinity Diagram
Improve tools in DMAIC (name 5)
Poka yoke TRIZ 5S SMED (single minute exchange dyes) FMEA (Failure Mode Effect Analysis) BIA Pugh matrix Design of Experiments Process Mapping 5 lean principles Hoshin Kanri
Control tools
Andon Control/Run Charts SPC Dash board Score Card