Six Sigma Tool Navigator: The Master Guide for Teams

2017-07-07 02:10:07

AKA

Surface Chart, Sarape Chart

Classification

Analyzing/Trending (AT)

Tool description

A stratum chart is an effective means to demonstrate cumulative additions of data that range from low to high and that are plotted along a horizontal time scale. Coloring or shading is used to differentiate among variables and to provide a quick interpretation of accumulation and relationships between plotted data.

Typical application

To show cumulative changes in data over time.

To display the effect of plotted variables, each variables' gradual change over time and relationships to each other.

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
2	Engineering
	Project management
3	Manufacturing
	Marketing/sales
	Administration/documentation
4	Servicing/support
	Customer/quality metrics
	Change management

links to other tools

before

Data Collection Strategy

Checksheet

Frequency Distribution (FD)

Trend Analysis

Sampling Methods

after

Major Program Status

Process Analysis

Monthly Assessment Schedule

Information Needs Analysis

Presentation

Notes and key points

Lines or curves cannot overlap.

Coloring or shading is needed to demonstrate the effect of cumulative changes in data plotted.

Step-by-step procedure

STEP 1 Collect historical data for variable to be plotted. See example TQM-Related Start-up Costs.

STEP 2 Scale the stratum chart to allow for highest cumulative number.

STEP 3 Plot the data along the horizontal time scale as shown in the example.

STEP 4 Color or provide pattern shading for variable data plotted.

STEP 5 Check the stratum chart for accuracy and provide date of issue.