Unit 7: Lean Six Sigma Principles
Expert-defined terms from the Professional Certificate in Performance Management in Quality Control course at London School of Business and Administration. Free to read, free to share, paired with a globally recognised certification pathway.
Alpha Risk (or Level) ) The probability of rejecting a true null hy… #
In other words, it is the risk of concluding that there is an effect when there is not. The alpha level is typically set at 0.05, meaning that there is a 5% chance of making a type I error.
Attribute Data Data that can be placed into distinct categories or classi… #
Attribute Data Data that can be placed into distinct categories or classifications, such as pass/fail, yes/no, or male/female.
Baseline A starting point or initial condition that is used as a referenc… #
In the context of Lean Six Sigma, a baseline is established at the beginning of a project to measure the current performance level of a process.
Capability Analysis A statistical analysis used to determine if a process… #
Capability analysis compares the variation of a process to the allowable tolerance range to assess the ability of the process to produce products or services within specification limits.
Control Chart A graphical tool used to monitor and control a process over… #
Control charts help to distinguish between common cause variation, which is inherent in the process, and special cause variation, which is caused by external factors and requires investigation and correction.
Correlation A statistical relationship between two variables where a chan… #
Correlation does not imply causation, meaning that a relationship between two variables does not necessarily mean that one variable causes the other to change.
Defect A nonconformance in a product or service that does not meet the sp… #
Defect A nonconformance in a product or service that does not meet the specified requirements or customer expectations.
Defect Per Million Opportunities (DPMO) A metric used to measure the numb… #
DPMO is calculated as the number of defects divided by the number of opportunities multiplied by one million.
Design of Experiments (DOE) A structured and systematic approach to plann… #
DOE involves identifying the factors that affect the outcome of a process, designing experiments to test the effects of these factors, and analyzing the results to identify the optimal settings for the factors.
DMAIC A problem #
solving framework used in Lean Six Sigma to improve existing processes. DMAIC stands for Define, Measure, Analyze, Improve, and Control.
Fishbone Diagram A cause #
and-effect diagram used to identify the root causes of a problem. Also known as an Ishikawa diagram or a Cause and Effect Diagram.
Histogram A graphical representation of the distribution of a data set #
Histograms show the frequency of each value or range of values in the data set.
Hypothesis Testing A statistical method used to test a hypothesis about a… #
Hypothesis testing involves setting up a null hypothesis and an alternative hypothesis, determining a significance level, and calculating a test statistic and p-value to evaluate the evidence against the null hypothesis.
Kaizen A continuous improvement approach that involves making small, incr… #
Kaizen emphasizes teamwork, collaboration, and the involvement of all stakeholders in the improvement process.
Lean A methodology focused on eliminating waste and improving flow in a p… #
Lean principles include defining value from the customer's perspective, mapping the value stream, eliminating non-value-added activities, and continuously improving the process.
Mean The average value of a data set #
The mean is calculated by adding up all the values and dividing by the number of values.
Median The middle value of a data set when it is arranged in order of mag… #
The median is the value that separates the data set into two halves.
Mode The most frequently occurring value in a data set #
Mode The most frequently occurring value in a data set.
Non #
Conformance A failure to meet the specified requirements or customer expectations. Non-conformances can result in defects in products or services.
Normal Distribution A continuous probability distribution that is symmetr… #
The normal distribution is often used to model the distribution of a data set in statistical analysis.
Operational Definitions Clear and concise definitions of measurements use… #
Operational definitions ensure that all stakeholders have a common understanding of what is being measured and how it is being measured.
Pareto Chart A graphical tool used to prioritize problems or issues based… #
Pareto charts show the relative frequency or size of each problem or issue in descending order, with the largest problem or issue at the left and the smallest at the right.
Process Capability The ability of a process to meet its specifications or… #
Process capability is measured using a statistical index called Cpk, which compares the variation of the process to the allowable tolerance range.
Process Control The ability to manage and maintain a process within its s… #
Process control involves monitoring the process using control charts and taking corrective action when necessary to maintain the desired level of performance.
Process Improvement The systematic approach to improving a process or pro… #
Process improvement involves identifying areas for improvement, analyzing the root causes of problems, and implementing and evaluating solutions.
Process Mapping A visual representation of a process that shows the steps… #
Process mapping helps to identify areas for improvement and standardize the process.
Range The difference between the largest and smallest values in a data se… #
Range The difference between the largest and smallest values in a data set.
Regression Analysis A statistical technique used to model the relationshi… #
Regression analysis can be used to predict the value of the dependent variable based on the values of the independent variables.
Six Sigma A methodology focused on reducing defects and improving process… #
Six Sigma principles include defining, measuring, analyzing, improving, and controlling (DMAIC) processes to achieve a defect rate of 3.4 defects per million opportunities.
Standard Deviation A measure of the dispersion or spread of a data set #
The standard deviation is calculated as the square root of the variance.
Statistical Process Control (SPC) The use of statistical methods to monit… #
SPC involves using control charts and other statistical tools to detect and correct deviations from the desired level of performance.
Variance A measure of the dispersion or spread of a data set #
The variance is calculated as the average of the squared differences between each value and the mean.
Value Stream Mapping A visual representation of the process flow from raw… #
Value stream mapping helps to identify opportunities for improvement and eliminate waste.
Value #
Added Activities in a process that add value from the customer's perspective. Value-added activities transform raw materials into finished goods or services that meet the customer's needs.
Variation The difference between individual measurements in a data set #
Variation can be caused by common causes, which are inherent in the process, or special causes, which are caused by external factors.
Yield The percentage of units produced in a process that meet the specifi… #
Yield is calculated as the number of units produced within specification limits divided by the total number of units produced.