# Cause Effect Graph Technique | Examples

## Cause Effect Graph-

• Cause Effect Graph is a popular black box testing technique.
• It illustrates the relationship between a given outcome and all the factors that influence the outcome graphically.

Here,

• A “Cause” stands for a distinct input condition that fetches about an internal change in the system.
• An “Effect” represents an output condition, a system state that results from a combination of causes.

## Applications-

• For analyzing the existing problem so that corrective actions can be taken at the earliest.
• For relating the interactions of the system with the factors affecting a particular process.
• For identifying the possible root causes, reasons for a particular effect, problem or outcome.

• It helps to determine the root causes of a problem or quality.
• It indicates possible causes of variation in a process.
• It identifies those areas where data should be collected for further study.
• It utilizes the team knowledge of the process by encouraging team participation.

## Steps For Drawing Cause Effect Diagram-

The following steps are followed-

• Identify and describe the input conditions (causes) and actions (effect).
• Build up a cause-effect graph.
• Convert cause-effect graph into a decision table.
• Convert decision table rules to test cases where each column of the decision table represents a test case.

## Problem-01:

Design test cases for the following problem-

If the character of the first column is ‘A’ or ‘B’ and the second column is a number, then the file is considered updated. If the first character is erroneous, then message x should be printed. If the second column is not a number, then message y should be printed.

## Solution-

### Step-01:

Identify and describe the input conditions (causes) and actions (effect).

The causes represented by letter “C” are as follows-

• C1 : The character in column 1 is ‘A’
• C2 : The character in column 1 is ‘B’
• C3 : The character in column 2 is a number

The effects represented by letter “e” are as follows-

• e1 : File update is made
• e2 : Message x is printed
• e3 : Message y is printed

### Step-02:

Build up a cause-effect graph-

### Step-03:

Convert cause-effect graph into a decision table-

 Test data Causes Effect A1 A2 A3 M1 M2 M3 1 0 0 0 0 1 1 2 0 0 1 0 1 0 3 0 1 0 0 0 1 4 0 1 1 1 0 0 5 1 0 0 0 0 1 6 1 0 1 1 0 0

## Problem-02:

Why Cause Effect Graphing Technique is Better Than Any Other Black Box Testing Technique?

## Solution-

• Boundary value analysis and equivalence partitioning do not explore combinations of input circumstances.
• These only consider the single input conditions.
• However, combinations of inputs may result in interesting situations.
• These situations should be tested.
• By considering all the valid combinations of equivalence classes, there will be large number of test cases.
• Many of these test cases will not be useful for revealing any new errors.

On the other hand,

• Cause Effect Graph is a technique that helps in selecting a high-yield set of test cases in a systematic way.
• It has a beneficial effect in pointing out incompleteness and ambiguities in the specifications.

To gain better understanding about Cause Effect Graph Technique,

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Summary
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Cause Effect Graph Technique | Examples
Description
Cause Effect Graph is a black box testing technique that illustrates the relationship between a outcome & the factors influencing the outcome graphically. Examples.
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Gate Vidyalay
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