Tool 186: Stem-And-Leaf Display

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.

Example of tool application