ptte 434 - lecture 3 quality organization & management ch 5 & 6
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PTTE 434 - Lecture 3Quality Organization & Management Ch 5 & 6
Quality Control
Process Management
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Lecture Objectives - Quality Control
Learn the definitions of control Understand Quality Control Understand what is meant by “statistically
significant.” Understand “Self-Control”
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Definition of Control
The process employed to consistently meet standards.
The control process is in the nature of a “feedback loop.”
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The Control Process
Choose the control subject, i.e., choose what is to be regulated.
Establish measurement. Establish standards of
performance: product/process goals.
Measure actual performance. Compare actual to standards. Take action on the difference.
PLAN
DO
CHECK
ACT
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Control Feedback Loop
Process Sensor Goal
ComparisonActuator
1
2 3
4
5
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RUMBA - Establishing Measures
Reasonable: Can you meet the requirements?
Understandable: Do you understand the requirements? Verify with the customer.
Measurable: Can it be determined if, and when you have met the requirement?
Believable: Do you and your employees agree with the requirement and that it can be met?
Achievable: Can the process meet the requirement? Is it realistic? If not, renegotiate with the customer.
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Measurement
Measurement is central to the process of quality control.
Effective measurement depends on a clearly defined process.
Effective measurement must be based on company objectives.
Don’t overlook the “cost of quality.”
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Measurement Process1 of 3 Define the purpose. Emphasize customer-related measurements. Focus on measurements that are useful -- not
just easy to collect. Provide for making measurements as close
as possible to activities they impact.
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Measurement Process2 of 3
Provide for participation from all levels in both planning and implementation.
Provide not only concurrent, also include leading and lagging indicators
Define, in advance, for data storage, collection, analysis and presentation of the measurements.
Seek simplicity
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Measurement Process3 of 3 Periodically evaluate the accuracy, integrity,
and usefulness of the measurements. Measurements alone cannot achieve
improvement - they only indicate whether, or not you have a problem and where the problems might exist.
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Self-Control
Ideally, quality should be controlled by the employee creating the product.
Examples: Rolls Royce Gear - Park City, UT O. C. Tanner, Co. - SLC, UT Woodland Furniture Co.- Idaho Falls, ID
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Deming’s Cycle
Act
A
P
D
C
Plan
Do
Check
A
P
D
C
Plan
Do
Check
A
P
D
C
Figure 5.3
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Control Subjects1 of 2 Should be aligned and linked to customer
parameters. Define work processes in terms of objectives,
process steps, process customers, and customer needs.
Recognize both the components of quality, i.e., freedom from defects, and product features.
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Control Subjects2 of 2 Potential subjects can be identified by
obtaining ideas from both customers and employees.
Quality control subjects must be viewed as being valid.
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Quality Control
Establish measurements Establish standards of performance Measure Actual Performance’ Compare to standards Take action on the difference
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Establish Measurement
A unit of measure: the unit used to report the value of the control subject, e.g., pounds, seconds, dollars
A sensor: a method or instrument that can carry out the evaluation and state the findings in terms of the unit of measure.
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Establish Standards of Performance
Legitimate: have official status Customer focused: external and internal Measurable: numbers. Understandable: clear to all In alignment: integrated with higher levels. Equitable: fair for all individuals
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Establish Standards of Performance
Insure each control subject has a quality goal.
Control subjects and goals
Control Subject Goals
Mean time between failures Minimum 5000 hours
Solder temperature of soldering process 500 degree F.
Overnight delivery 99.5% delivered prior to 10:30 a.m. next morning
Relative quality rating At least equal in quality to competitors A and B
Customer retention 95% of key customers from year to year
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Quality Responsibility Spreadsheet
Process Controlfeatures
ControlSubject
Unit ofMeasure
Type ofSensor
Frequency ofMeasurement
Sample Size Criteria formakingdecision
Responsibilityfor decision
making
Wave solderconditionsSolder Temp.
Degree F(oF)
Thermocouple Continuous N/A 510 oFreduce heat500 oFincrease heat
Operator
Conveyor Speed Feet per minute(Ft./min)
4.5 ft/min 1/hour N/A 5 ft/minreduce speed4 ft/minincrease speed
Operator
Alloy purity % totalcontaminates
Lab chemicalanalysis
1.5% max 15 grams At 1.5% drainbath, replacesolder
Processengineer
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Quality Score Card 1st quarter
MeasurementCategory
CustomerSpecifications
ActualPerformance
Actual
EvaluationExcellent Poor
Underwriting
Turnaround time 4 hours 99.9% 4.6 5 4 3 2 1
Accessibility 100% 99.5% 4.2 5 4 3 2 1
KnowledgeableConsistentapplication ofguidelines
95.5% 3.2 5 4 3 2 1
Billing
Timeliness 3rd - 5th of month 99.9% 4.6 5 4 3 2 1
Completeness 100% 98.9% 3.8 5 4 3 2 1
Claims
Timely Payments 30 days 84% 2.5 5 4 3 2 1
Work out cycletime
To guidelines100%
95% 3.1 5 4 3 2 1
Sales
Meeting frequencyMonthly /quarterly 100% 6+ 5 4 3 2 1
KnowledgeAnswer questionswhen asked
86% 2.6 5 4 3 2 1
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Compare to Standards
Sometimes comparison is simple - if solder temp. exceed 510o F, decrease heat, if between 500o F and 510o F, do nothing, if less than 500o F, increase heat.
Other times, must determine whether it is an apparent difference, or real “statistical” difference in variation.
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Process CapabilitySlide 1 of 4
Process Stability and Capability Once a process is stable, the next emphasis is
to ensure that the process is capable. Process capability refers to the ability of a
process to produce a product that meets specifications.
Six-sigma program such as those pioneered by Motorola Corporation result in highly capable processes.
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Process CapabilitySlide 2 of 4
Six-Sigma Quality
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Process CapabilitySlide 3 of 4
Process Versus Sampling Distribution To understand process capability we must first
understand the differences between population and sampling distributions.
Population distributions are distributions with all the items or observations of interest to a decision maker.
A population is defined as a collection of all the items or observations of interest to a decision maker.
A sample is subset of the population. Sampling distributions are distributions that reflect the distributions of sample means.
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Process Capability
The Difference Between Capability and Stability? Once again, a process is capable if individual
products consistently meet specifications. A process is stable if only common variation is
present in the process.
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Process Control Charts
Implications of a Process Out of Control If a process loses control and becomes
nonrandom, the process should be stopped immediately.
In many modern process industries where just-in-time is used, this will result in the stoppage of several work stations.
The team of workers who are to address the problem should use a structured problem solving process.
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Control Charts
Each point representsdata that are plotted
sequentially
Upper ControlLimit (UCL)
Lower ControlLimit (LCL)
CenterLine (CL)
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Process Control Charts
Interpreting Control Charts The figures in the next several slides show different
signals for concern that are sent by a control chart, as in the second and third boxes. When a point is found to be outside of the control limits, we call this an “out of control” situation. When a process is out of control, the variation is probably not longer random.
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Process Control Charts
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Process Control Charts
Control Chart Evidence for Investigation
improved performance.
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Process Control Charts
Control Chart Evidence for Investigation
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Process Control Charts
Control Chart Evidence for Investigation
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Ch 6: Lecture Objectives - Process Control Understand “functional” versus “process”
management Understand how to analyze process data. Learn the benefits to process analysis and
control. Learn about “Value Stream” mapping
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Functional and Process Management
Billing
Product Development
Distribution
Dev
elop
men
tM
anuf
actu
ring
Mar
ketin
gSe
rvic
e
Supp
ort
Functional Objectives
Pro
cess
Ob j
e ct i
v es
Customer
Customer
Customer
Mission/Vision
Strategic Plan
Key business objectivesBoard of
Directors
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Value Stream Mapping
• A simple, visual approach to:
Focusing on a “product family”
Creating a clear picture of current material and information flow associated with that product family
Identifying Lean tools and techniques that can improve flow and eliminate waste
Incorporating those ideas in a new picture of how material and information “should” flow for that product group
Creating an action plan that makes the new picture a reality for that product family
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Value Stream Mapping
Value stream mapping is a paper and pencil tool that helps you to see and understand the flow of material and information as a product or service makes its way through the value stream. Value stream mapping is typically used in Lean, it differs from the process mapping of Six Sigma in four ways:
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Value Stream Mapping
It gathers and displays a far broader range of information than a typical process map.
It tends to be at a higher level (5-10 boxes) than many process maps.
It tends to be used at a broader level, i.e. from receiving of raw material to delivery of finished goods.
It tends to be used to identify where to focus future projects, subprojects, and/or kaizen events.
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Value Stream Mapping
A value stream map (AKA end-to-end system map) takes into account not only the activity of the product, but the management and information systems that support the basic process. This is especially helpful when working to reduce cycle time, because you gain insight into the decision making flow in addition to the process flow. It is actually a Lean tool.
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Value Stream Mapping It helps you visualize more than just the single-process level, i.e.
assembly, welding, etc. it helps you see more than waste
It helps you see the sources of waste in your value stream it provides a common language for talking about manufacturing processes it makes decisions about the flow apparent, so you can discuss them
It ties together lean concepts and techniques helps you avoid "cherry picking"
It forms the basis of an implementation plan it shows the linkage between the information flow and the material flow
It is much more useful than quantitative tools and layout diagrams that produce a tally of non-value added steps, lead time, distance traveled, the amount of inventory, and so on.
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Current State Map
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Future State Map
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Value Stream Mapping Movie
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