Global Supply Chains Midterm
Pareto Charts
Helps you make priorities visible by showing the frequency at which each cause occurs. You can then rank order the causes of variability.
Reliability
How dependably can the service provider provide promised service?
External Failure Costs
Remedying defects discovered by that customer: Costs failures that are detected after they are transferred to the customer
Quality has more influence on a company than any other value-added dimensions.
True
The core objective in six sigma is to reduce variation in processes.
True
You need to evaluate services quality a little differently than you evaluate product quality.
True
The following indicate that any process is out of control:
- A single point plots outside the control limits. - Two out of three successive points are on the same side of the centerline and farther than 2 σ from it. - Four out of five successive points are on the same side of the centerline and farther than 1 σ from it. - A run of eight in a row are on the same side of the centerline. - Any consistent or persistent pattern tells you that your process includes systematic variation.
Armand V. Feigenbaum
- Control must start with identification of customer quality requirements and end only when the product has been placed in the hands of a customer who remains satisfied. - "Hidden plant" to signify that 15 to 40% of capacity exists to find & fix poor work.
Joseph M. Juran
- Over 80 percent of quality defects are controllable by management. - The quality trilogy: Plan, Control & Improve. - Identify the few vital projects. - Discover the causes of the problem!
A control chart that measures attributes measures what?
Characteristic that has a discrete value and can be counted
People
Consider everyone who touches the process. What are the sources of human error? Some classic issues include poor training, fatigue, and lack of experience.
Prevention or Avoiding Quality Problems
Costs of designing and maintaining the quality management system.
Appraisal Costs
Costs of evaluating produced or purchased information, processes, products, and services
Quality management can make or break your company's future
Customers don't just value quality - they expect it
Kaoru Ishikawa
Developed Quality Control Circles (QCCs) & "fishbone" diagrams. Expanded TQC to all non-specialists & labeled it Company-Wide Quality Control (CWQC). Emphasized statistical methods on factory floor.
Conformance
Does the product conform to design specifications?
Reliability
Does the product consistently perform as it is supposed to over time?
Performance
Does the product do what you want it to?
Aesthetics
Does the product look, sound, taste, or smell the way it should?
Features
Does the product possess the features you are looking for?
Philip Crosby
Doing things right the first time adds nothing to the cost of your product or service. Doing things wrong is what costs money.
Which "Quality of Product" dimension would you be assessing when asking the question, "How long will the product perform or last, and under what conditions?"
Durability
Guardbanding
Engineers set product specifications tighter than they need to be - increases production costs and lengthens lead times without improving quality
Machines
Evaluate the equipment and technology used in the process. Are there any issues like poor maintenance, worn equipment, or the use of the wrong equipment that hurt process performance?
As a rule of thumb, a Cpk of less than 1.5 indicates that your process can meet your desired quality levels.
False
The Ishikawa cause-and-effect diagram is also known as the
Fishbone Diagram
Perception
For any dimension that cannot be observed directly, does the product seem like a high-quality product?
Assurance
How knowledgeable and courteous are the service employees and how well do they convey trust and confidence?
Durability
How long will the product perform or last, and under what conditions?
Tangibles
How pleasing is the appearance of the physical facilities, equipment, personnel, and communication materials?
Empathy
How well does the service provider provide caring, individualized attention to its customers?
Responsiveness
How willing, able, and promptly is the service provider to help you?
By investing in prevention and appraisal costs, your real goal is what?
Identify and eliminate the causes of problems before they occur
Serviceability
Is the product relatively easy to maintain and repair?
"Quality is free"
It costs less to make quality products than it does to fix poor-quality products
Methods
Look at every aspect of the process. How is it performed? How do policies, procedures, et cetera affect process performance?
W. Edward Deming
No permanent impact has ever been accomplished in improvement of quality unless top management carries out their responsibilities. These responsibilities never cease; they continue forever.
Which of the following tools would you use to identify the most-likely cause of a quality problem?
Pareto Chart
Internal Failure Cosrts
Remedying defects before delivery to customer: costs of failure that are detected before they are transferred to the customer
Which "Quality of Service" dimension would you be assessing when asking the question, "How willing, able, and promptly is the service provider to help you?"
Responsiveness
The tool that monitors processes and keeps them production high-quality products is?
Statistical process control
Six Sigma is built on which very critical fact?
Variability in a process produces defects, errors, and waste
In the process capability ratio, six sigma captures almost 88% of the process variability.
False
Six Sigma
A disciplined, data-driven approach for improving quality by removing defects and their causes
Quality Dimensions
- product quality - service quality
Your real goal
Identify and eliminate the causes of problems before they occur
Environment
Question how environmental conditions—e.g. location, time, temperature, et cetera—influence the process.
Genichi Taguchi
- Quality is a virtue of design. The "robustness" of products is more a function of good design than of on-line control, however stringent, of manufacturing processes. - You gain virtually nothing in shipping a product that just barely satisfies the corporate standard over a product that just fails. Get on target, don't try to stay in-spec.
Which of the following is a definition of Quality?
- conformance to specifications - whether or not a product or service lives up to customer expectations
Quality Defined
- conformance to specifications - whether or not a product/service lives up to customer expectations
Total Quality Management Core Principles
- customer-focused - leadership - involvement of people - process approach - system approach to management - continuous improvement - fact-based decision making - mutually beneficial supplier relationships
Which of the following are potential sources of variation in the Ishikawa cause-and-effect diagram?
- materials - measurements - environment
Customer-Service Horror Stories
- poor service - bad attitude - misguided policies
To achieve quality at the source, you need to focus on which of the following?
- prevention - personal responsibility - standardization
The total-cost-of quality framework breaks out quality costs into which four categories
- prevention costs, appraisal costs, internal failure costs, external failure costs
Which of the following is not one of the steps in W. Edward Deming's PDCA cycle?
- procrastinate - calculate
Statistical process control charts measure what?
- variables - attributes
Improving Process Capability
1. Change the specifications 2. Modify the process 3. outsource
Product Quality Dimensions
1. Performance 2. Features 3. Flexibility 4. Durability 5. Conformance 6. Serviceability 7. Aesthetics 8. Perception
W. Edward Deming's four-step—Plan, Do, Check, Act (PDCA)
1. Plan - define the problem and identify the root cause. 2. Do - implement your corrective action to solve the problem. 3. Check - check to see if the corrective action really solved the problem. 4. Act - if your solution worked, make it a formal part of the process. Share your process, solution, and results wherever and whenever possible.
To consistently achieve quality at the source:
1. prevention - avoid problems in the first place 2. personal responsibility - promote a "stop and fix-it" mentality 3. standardization - standardized work makes defects more obvious when they occur
Service Quality Dimensions
1. tangibles 2. reliability 3. responsiveness 4. assurance 5. empathy
Suppose that the design engineering team set the specifications for length of a stamped sheet-metal part at 10 inches (T) with acceptable tolerances of ±.05 inches (USL and LSL). The average length of the products produced by the actual stamping process is 9.995 inches (m) with a standard deviation of .005 inches (s). What is your Cp?
3.33
Statistically, six-sigma performance produces fewer than _____ defects per million opportunities for an error for defect.
3.4
Control Chart for Attributes
A characteristic that has a discrete value and can be counted (e.g., is the product "good" or "defective" or how many blue M&Ms are in the package).
Which "Quality of Product" dimension would you be assessing when asking the question, "Does the product look, sounds, taste, or smell the way it should?"
Aesthetics
Variability
All processes, no matter how well they are performing, include some variation. The amount of random variability in a process will largely determine how far the upper and lower limits are from the target.
Measurements
Ask, "What data do you have to help you better understand process relationships and performance?"
Materials
Assess ALL of the materials used in the process. How do defective, damaged, or poorly specified materials affect performance?
Which of the following helps you make priorities visible by showing the frequency at which each cause occurs?
Pareto diagram
What are the four stems to E. Edward Deming's four-step continuous improvement processes?
Plan, Do, Check, Act
Target
Processes are designed to produce to a specific quality target. You build your control chart—i.e., the upper and lower limits—around this target.
A control chart that is constructed using a range is called a/an...
R-Chart
Six Sigma's Core Objective
Reduce process variation
With respect to control chart logic, processes that are designed to produce to a specific quality number is called?
Target
Control Chart for Variables
Things that can be measured on a continuum of values like weight and volume.
Shigeo Shingo
Toyota's engineering genius who developed JIT philosophy, Single-minute Exchange of Die (SMED), & "Zero Quality Control" which aims to eliminate inspection through "poka-yoke"—mistake proofing production operations.
In the process capability ratio, if the upper and lower specification limits are greater than the process variability, you can be pretty confident that the process can achieve your desired quality level.
True
How is the statistical concept of six sigma used?
Uses tools to help you identify which type of variation is present in your processes as well as how to address that variation to improve your process
With respect to control chart logic, processes performed include some variation is called?
Variability
Process Capability Analysis
Verify that the process is capable of consistently producing product within the design specifications your engineers have set
What does a process capability analysis allow you to do?
Verify that your process is capable of performing at your desired quality level
Which quality guru is responsible for the four step—Plan, Do, Check, Act (PDCA)—cycle that is used by almost every global manufacturer today?
W. Edward Deming
Confidence
You set control limits based on the level of confidence you want to have that the process really is out of control (typically 3 or 99.74%). If a sample of data you collect from the process falls above the upper limit or below the lower limit, you can be confident something unusual is going on—that is, the process is out of control and you need to fix it.
Under what circumstances would you use process capability analysis?
You want to verify that the process is capable of consistently producing good outputs
The Ishikawa cause-and-effect diagram (aka the fishbone diagram)
a simple tool that helps you identify, isolate, and break down the major causes of variation
process capability ratio
compares acceptable tolerances (set by your engineers) with the process' actual variation so you can assess the process' ability to achieve required quality levels
In the process capability ratio, the farther off center the process is operating, the more likely it is to produce unacceptable parts. This adjustment is represented by which symbol?
k
Six Sigma Statistical Significance
six sigma performance produces fewer than 3.4 defects per million opportunities for an error or defect
If special cause variation is present in a process
then the process is out of control
A control chart that is constructed using a mean is called a/an...
x̄ chart
Pilot Test
you want to know how the process is going to work in real life