Tool 14: Bar Chart

AKA

Bar Graph

Classification

Analyzing/Trending(AT)

Tool description

A simple bar chart is useful to present information for a quick problem or opportunity analysis. It provides a comparison of quantities of items or frequencies of events within a particular time period.

Typical application

• To display a "snapshot" comparison of categories.

• To depict the relationship between variations over time.

• To illustrate process variability or trends.

• To indicate a potential problem area (high or low frequencies).

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

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

links to other tools

before

• Data collection strategy

• Frequency Distribution (FD)

• Checksheets

• Events log

• Observation

after

• Pie Chart

• Stratification

• Variance Analysis

• Pareto chart

• Presentation

Notes and key points

• Care should be taken not to insert more than five bars or cover more than five time periods. This would make the Bar Chart cluttered and difficult to interpret.

• f = frequency

Step-by-step procedure

• STEP 1 Collect data from sources such as a checksheet. See example Customer complaints.

• STEP 2 Construct a bar chart. Apply the 3:4 ratio rule. The height of the Y axis must be 75 percent of the length (100 percent) of the X axis.

• STEP 3 Label the axes and insert the bars as shown in the exaple.

• STEP 4 Check all information and date the bar chart.

Example of tool application