This blog is created to share knowledge on modern manufacturing systems.
Showing posts with label Quality. Show all posts
Showing posts with label Quality. Show all posts
Saturday, July 25, 2020
What is Quality Circle? Seven Basic Quality Circle Tools
Quality Circle
A Voluntary group of employees who work on similar tasks or
share a similar area of responsibility to improve products or processes
- Work on the principle that employee participation in decision-making & problem-solving improves the quality of work
- Encourage to elect the leaders towards the end of the training period
- Agree to meet on a regular basis to discuss & solve problems related to work
- All members of a Circle need to receive training
- Members need to be empowered
- Members need to have the support of Senior Management
The Japanese description of the effectiveness of a quality
circle is expressed as:
‘It is better for one hundred people to take one step
than for one person to take a hundred’
Sunday, October 1, 2017
Acceptance Sampling, Producer’s Risk(α), Consumer’s Risk (β) & Acceptable Quality Level (AQL)
Acceptance Sampling
Acceptance sampling is concerned with inspection and
decision making regarding the entire lot/production/shipment
- A form of inspection used to accept or reject whole lot based on sample information
- Not consistent with TQM or Zero Defects philosophy
- Producer & customer agree on the number of acceptable defects
- A means of identifying not preventing poor quality
Statistical Process Control (SPC), Basic Procedure of Control Chart.
Statistical Process Control (SPC)
Statistical evaluation of the output of a process during
production
- Goal is to make the process stable over time & then keep it stable unless the planned changes are made
- Statistical description of stability requires that ‘pattern of variation’ remains stable over time, not that there be no variation in the variable measured
- Process is in control has only random cause variation (inherent variability of system)
- When the normal functioning of the process is disturbed by some unpredictable events, special cause variation is added to common cause variation
Statistical Quality Control (SQC) & Process Variability
Statistical Quality Control (SQC)
A quality control system using statistical techniques to
control quality by performing inspection, testing & analysis to conclude
whether the product is as stated or designed quality standard
- Relying on the probability theory, evaluates batch quality & controls the quality of processes or products
- Makes the inspection more reliable & less costly
SQC is used to describe the set of statistical tools used by
quality professionals
- Descriptive statistics
- Used to describe quality characteristics & relationships
- Acceptance sampling
- Used to randomly inspect a batch of products to determine acceptance or rejection of entire lot based on the results
- Does not help to identify and catch the in-process problems
- Statistical process control (SPC)
- Involves inspecting the output from a process & identifying in-process variation
- Quality characteristics are measured & charted
What is Quality Inspection? How Much to Inspect, How Often & Where to Inspect in the Process.
Inspection
An appraisal activity that compares goods or services to a
standard
- Well-designed processes little inspection is necessary, inspection cannot be completely eliminated
In lean organizations, inspection is less of an issue than
it is for other organizations, because have extra emphasis on quality in the
design of both products/processes & workers have responsibility for quality
(quality at the source).
What is Quality control? Approaches to quality assurance.
Quality control
A process that evaluates output relative to a standard &
takes corrective action when output doesn’t meet standards
- The operational techniques & activities (a system for measuring & checking) used to fulfill the requirements for quality
- Incorporates a feedback mechanism system to explore the causes of poor quality or unsatisfactory performance & takes corrective actions
- Suggests when to inspect, how often to inspect, & how much to inspect.
The foundations of modern quality management: The Gurus
Walter A. Shewhart
- Pioneer of Modern Quality Control
- Founder of the control chart “father of statistical quality control.”
- Originator of the plan-do-check-act cycle
- Perhaps the first to successfully integrate statistics, engineering, & economics
W. Edward Deming
- Theory of variance: controllable & uncontrollable variance
- PDCA cycle: Core element is ‘Management Team’
- Fourteen points for quality and productivity.
- Seven deadly sins and diseases.
- Out of Crisis (Having a satisfied customer is not enough)
- Profit in the business comes from repeat customers, customers that boast about your product & service & customers that bring friends with them
Quality Problem Solving
Problem Solving
Basic steps in problem solving
- Step 1: Define the problem & establish an improvement goal
- Step 2: Develop performance measures & collect data (check sheet, scatter diagram, histogram, run chart, & control chart)
- Step 3: Analyze the problem (Pareto chart, cause-and-effect diagram)
- Step 4: Generate potential solutions (brainstorming, interviewing, surveying)
- Step 5: Choose a solution
- Identify the criteria for choosing a solution & select the best one
- Step 6: Implement the solution
- Keep everyone informed
- Step 7 : Monitor the solution to see if it accomplishes the goal.
Total Quality Management (TQM), Basic Principles & Implementation of TQM
Total Quality Management (TQM)
A philosophy that involves everyone in an organization in a
continual effort to improve quality & achieve customer satisfaction. There
are three key philosophies
- Never-ending push to improve, which is referred to as continuous improvement
- Involvement of everyone in the organization
- Customer satisfaction, which means meeting or exceeding customer expectations
What is Quality? Dimensions & Determinants of Quality. Consequences of Poor Quality
Quality
Quality is consistent conformance to customers’
expectations, in other words, ‘doing things right’
- Major influence on customer satisfaction or dissatisfaction
Another way to think about quality is the degree to which
performance of a product or service meets or exceeds customer expectations
The Dimensions of Quality
Product & service quality is often judged on eight dimensions
of quality
The Determinants of Quality
The degree to which a product successfully satisfies its
intended purpose
- Design
- Quality of design (Intention of designer to include/exclude feature)
- How well the product conforms to the design
- Quality of conformance (The degree to which goods/services conform to the intent of the designers)
- Ease of use
- User instructions, intended purposes, ways for functioning properly & safely
- Service after delivery
- Recall & repair of the product, adjustment, replacement or buyback
Benefits of Good Quality
- An enhanced reputation for quality
- Greater customer loyalty
- The ability to command premium prices
- An increased market share
- Fewer production or service problems
- Lower liability costs
- Higher productivity
- Higher profits
The Consequences of Poor Quality
- Loss of business
- Liability
- Productivity
- Costs
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