Six Sigma Tool Navigator: The Master Guide for Teams

2017-07-07 02:10:07

AKA

Stem-And-Leaf Diagram

Classification

Analyzing/Trending (AT)

Tool description

The stem-and-leaf display, as developed by John Turkey in 1977, displays the actual numerical values or numbers as collected over a specified period of time. Similar to a histogram, it shows distribution, numerical order, and variation in a process.

Typical application

To display original data for further analysis.

To obtain an idea of overall process variation.

Problem-solving phase

→	Select and define problem or opportunity
→	Identify and analyze causes or potential change
	Develop and plan possible solutions or change
	Implement and evaluate solution or change
→	Measure and report solution or change results
	Recognize and reward team efforts

Typically used by

1	Research/statistics
	Creativity/innovation
	Engineering
	Project management
	Manufacturing
2	Marketing/sales
3	Administration/documentation
	Servicing/support
4	Customer/quality metrics
	Change management

links to other tools

before

Data Collection Strategy

Frequency Distribution (FD)

Checksheet

Normal Probability Distribution

Questionnaires

after

Histogram

Descriptive Statistics

Problem Specification

Process Analysis

Problem Analysis

Notes and key points

Construct a steam-and-leaf display with 5–15 stems. All leaves (scores, numbers, or measurements) are attached to a specific stem.

Step-by-step procedure

STEP 1 Collect and summarize the data to be displayed.

STEP 2 Construct a stem-and-leaf display. Stems will reflect the leading digit of numbers: See example Division "B" Rework Hours for August.

STEP 3 Insert the leaves on the basis of all numbers collected and recorded, the raw data.

STEP 4 Verify that all numbers from the raw data table have been correctly displayed in the stem-and-leaf display. Date the display.