The Chi-Square Test is a hypothesis test that determines whether a statistically significant difference (aka variance) exists between two or more independent groups of discrete data, ruling out chance. It is useful for determining whether or not improvement implementations have been successful. This test is performed on count data from…
What is a Check Sheet? A Check Sheet is a simple tally sheet used to systematically collect data on the frequency of an occurrence (e.g., the frequency of defects). Useful for all phases of DMAIC, Check Sheets are best used when the data can be collected by the same person or in…
Central Tendency is the "center point" of a process distribution. It can be measured in one of three ways: Median (middle most data point in a sorted data set), Mode (data value repeated most often), and Mean (average). For a better understanding of Central Tendency and an overview of Lean Six…
A Business Case is a broad statement that helps sell or justify a specific improvement opportunity to the senior leadership or stakeholders in an organization. This is generally part of a Lean Six Sigma Project Charter. A Business Case defines how the customer is negatively impacted, how long they’ve been…
Brainstorming is a free-thinking group method for generating ideas to handle a challenging situation. An underlying maxim for Brainstorming is "from quantity comes quality." The primary objective of Brainstorming is to encourage innovation and out-of-the-box thinking. To achieve this goal, the Brainstorming session is performed with no editing: analysis, discussion,…
A Box Plot, or Box and Whisker Plot, is a graphical view of a data set that is divided into fourths or “quartiles.” It shows the center and spread of a data set but is most useful when comparing two or more “strata” or data sets such as the cycle…
A Baseline Measure results from data collected to establish the initial capability of a process to meet customer expectations. By collecting a baseline prior to making any changes to the process it is possible to determine if solutions implemented later on have the desired impact. For a better understanding of…
Attribute data refers to categories or counts that can only be described in whole numbers; i.e. you can’t have half a defect or half a customer. This type of data is the opposite of continuous or variable data (temperature, weight, distance, etc.). Typical Attribute Data refers to the number of…
Assumption Busting is a brainstorming and questioning technique that does two things: Identifies and challenges conventional assumptions Eliminates them if they are obstacles to optimal solutions For a better understanding of Assumption Busting and an overview of Lean Six Sigma, check out our Free Lean Six Sigma Yellow Belt Training, Green…
The Analyze Phase is the third phase of the DMAIC process, and focuses on identifying the root cause (or causes) of a process problem. The Analyze Phase requires data and knowledge gleaned from the previous Define and Measure phases of DMAIC. This phase focuses on analysis of the data and…