Chapter 9 - Quality Control
Describe what run chart analysis will do for you.
A simple graph that displays data in time sequence; also known as a runs chart, time series graph, time series plot, trend chart, run-sequence plot, line graph, and run diagram.
Explain the difference between Cp and Cpk. Calculate Cp and Cpk given supplied process information.
Cp measure is that it requires the process to be centered in the specification rage for an accurate measure of process capability. Because of this problem, another more widely used measure (Cpk) has been devised. Cpk more accurately reflects the actual process capability, it is the measure commonly used by industry.
Explain the targeted Cp and Cpk values.
Cp values should be greater than or equal to one, and Cpk should be 0 or 1.
Describe how Pareto analysis works.
Find the defects to try and eliminate first and then work at doing so
Describe the first stage or step in bringing a process under control.
Flowcharting is done first - describe the flow of work and the relationships among steps in the process
Describe what's meany by Six-Sigma quality.
Improves the quality of process by identifying and removing the causes of defects (errors) and minimizing variability in manufacturing and business processes. It use a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization (champions, black belts, green belts, yellow belts. Ect) who are experts in these methods.
Describe what capability analysis does.
Is simply the ability of the process to meet or exceed the technical specifications obtained from customers.
Describe the two mistakes managers can make when looking at an individual data point without the benefit of control chart limits
Two mistakes that managers make: Assume a process is in control, when it's actually out of control Assume a process is out of control, when it's actually in control
strategy map
a causal map that shows the relationships between critical elements of an organization's business system
service quality
a customer's long-term overall evaluations of a service provider
Pugh Matrix
a decision tool that facilitates a disciplined, team-based process for concept generation, evaluation, and selection
process capability
a lean sigma methodology that measures the ability of a process to consistently meet quality specifications
RACI Matrix
a matrix that identifies the roles and responsibilities for all stakeholders involved in any process where R=Responsible, A=Authority, C=Consulted, I=Informed
sigma level
a metric that measures the defect rate for a process in terms of the standard normal distribution which an assumed shift in the mean of 1.5 standard deviations
zero defects
a quality management philosophy that stresses elimination of all defects
SERVQUAL
a service quality instrument (survey) that measures the gap between customer expectations and perceptions after a service encounter
seven tools of quality
a set of seven fundamental tools used to gather and analyze data for process improvement: histogram, Pareto Chart, check sheet, control chart, fishbone (Ishikawa) diagram, process map (flowchart), and scatter diagram (scatterplot)
Statistical Process Control (SPC) and Statistical Quality Control (SQC)
a set of statistical tools that can be used to monitor and maintain the performance of a process
Total Productive Maintenance (TPM)
a systematic apron ch to ensure uninterrupted and efficient use of equipment
Total Quality Management (TQM)
a term popular in the 1980s that emphasized quality throughout all areas of the organization, with a focus on employee participation and customer satisfaction
Root Cause Analysis (RCA)
a tool used to identify the origins of an adverse event (or events) after the fact
PDCA (Plan-Do-Check-Act)
a well-known four-step approach for process improvement
Voice of the Customer (VOC)
customer opinions, perceptions, needs, desires (both stated and unstated), preferences, expectations, and requirements
six sigma
process improvement programs that historically focused on reducing variation
supplier qualification and certification
programs designed by purchasing organizations to test if suppliers can meet certain standards
performance quality
the degree to which the product design meets customer requirements
socio-technical design
the process of defining and combining tasks to create work for an individual or group of individuals
Outline the steps in designing a quality control system.
1. To identify the critical points in each of the processes where inspection and testing are needed. 2. To decide on the type of measurement to be used at each inspection point -two types of data: variables, attribute 3. To decide on the amount of inspection to use 4. To decide who should do the inspection. (usually worker to inspect their own is the best, customer might do at some case)
Compare and contrast Lean and Six Sigma.
Lean: reduce waste (non-value-added activities); waste can include, in part, defects. Six Sigma: reduce defects as seen by customers. Objectives, organization, methods, types of project are different.
Describe management's next concern once a process is under control.
Perform analysis to figure out why the process left control and figure out how to prevent this from happening again
Explain the DMAIC framework.
Six Sigma is a systematic method for process improvement that often uses the five steps defined by the acronym DMAIC -Define: the process is selected for improvement, and the project charter is specified -Measure: Quality variables valued by the customer are measured, and goals are set for improvement. -Analyze: The root causes of the current defect levels are identified, and alternatives are considered for process changes. -Improve: the process is changed and checked for improvement -Control: this step ensures that the process improvement is not lost over time.
Explain what it means when a process is in statistical control and draw an example of this situation.
Statistical process control (SPC) is a method of quality control which uses statistical methods. SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or scrap). SPC can be applied to any process where the "conforming product" (product meeting specifications) output can be measured. Key tools used in SPC include control charts; a focus on continuous improvement; and the design of experiments. An example of a process where SPC is applied is manufacturing lines
Describe Cause-and-Effect diagramming - its purpose and how it works.
They are frequently constructed by quality improvement teams that work to identify a wide variety of possible causes for a problem to narrow down and take corrective action.
SIPOC Diagram
an acronym for Suppliers, Inputs, Process, Outputs, and Customers, which is a tool used to identify all relevant elements of a process for the purpose of process improvement