Tool 171: Run Chart

AKA

N/A

Classification

Analyzing/Trending (AT)

Tool description

A run chart is a simple monitoring tool that indicates a trend of change or process over a specified time. Observed data is plotted in sequence and connected by a line to show runs. Run charts can be used for monitoring any variation from an average, the increasing/decreasing trends in performance or defects, or any other change in normal data patterns.

Typical application

• To observe process variation over time.

• To plot data for the purpose of identifying any changes or trends in the average.

• To receive an early warning of a potential problem due to an observed pattern of plotted data that shows an undesirable trend or 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
3	Project management
4	Manufacturing
	Marketing/sales
	Administration/documentation
	Servicing/support
	Customer/quality metrics
2	Change management

links to other tools

before

• Checksheet

• Observation

• Data Collection Strategy

• Polygon

• Surveying

after

• Problem Specification

• Process Analysis

• Problem Analysis

• Potential Problem Analysis (PPA)

• Monthly Assessment Schedule

Notes and key points

• A run chart is simply a chart showing runs and trends. It is not as powerful as a control chart that determines if a process is in or out of control on the basis of calculated upper and lower control limits.

• A rough indication of a potential problem may be the consecutive increase or decrease of six or more points in row (a run).

• Another indication of a process change may be the consecutive run of nine or more points on one side of a plotted average () center line of the run chart.

• Plot at least twelve data points to increase the probability of observing a meaningful pattern.

Step-by-step procedure

• STEP 1 If possible, collect historical data of the process to be observed. This will provide a baseline, or an average, for the run chart to be constructed. See example "Tools for Teams" Training Participant Attendance.

• STEP 2 Develop a run chart showing time horizontally and a discrete or continuous interval scale vertically.

• STEP 3 Plot the observations (measurements) in sequential order as they are collected. Connect data points with straight lines.

• STEP 4 As the run chart is developed, check for trends, variations, or indications of potential problems.

• STEP 5 Date and save run charts for formulating a problem specification.

Example of tool application