How does a simple path segment play a role in data flow testing?

Whenever you have discussed about the data flow testing you must have came across the term simple path segments while discussing about the strategies for data flow testing. Many of us are not quite clear with the concept of the simple path segments and what role have they got to play in the data flow testing. This article is all about the simple path segments and the role that they have got to play in the data flow testing. 

First we shall brief up ourselves with the concepts of the data flow testing before moving on to the topic of the simple path segments and their role. 

What is Data Flow Testing

- Data flow testing includes all those strategies that have been based up on the selection of the paths via the control flow of the program for discovering the sequence in which the events related to the object’s status take place.

- A primary bug assumed during the data flow testing is that though the control flow is generally correct, there is some fault with the software system or application since the data objects are not available when they are supposed to be or weird things happen to the data objects. 

- Even if some problem is found to preside in the control flow of the program it is initially detected by the data flow analysis. 

- One of the most aiding tool in the data flow testing are the control flow graphs which are the graphs consisting of directed links and nodes. 

- The objective of the data flow testing is to discover the deviations in the data flow. Three types of data objects have been defined namely:

1. Killed or undefined
2. Defined
3. Usage

And some nine kinds of anomalies have been defined:

1. dd: harmless but suspicious
2. dk: might be a bug
3. du: a normal case
4. kd: a normal situation
5. kk: harmless but might be containing bugs
6. ku: a bug or error
7. ud: not a bug because of re- assignment
8. uk: a normal situation
9. uu: a normal situation

These anomalies are detected by the means of two anomaly detection techniques namely:

1. static anomaly detection technique and
2. dynamic anomaly detection technique

All the strategies involved in the process of data flow testing are structural. Data flow testing and path testing strategies have so many things in common. But one of difference between them is made by what one takes in to account for testing. Path and data flow testing both are emphasized up on the raw connectivity of the graph but in addition to this the data flow testing also focuses up on what happens to the data objects. There are so many terminologies associated with the data flow testing and simple path segment is one of them. The others are:

1. definition clear path segment
2. loop free path segment
3. du path segment

What is Simple Path Segment

We shall now define what a simple path segment is! 

- Any path in which the same node is visited twice at the most, such a path is called a simple path segment. 

- One can easily make out why a simple path segment is called so! 

- It is called so because it does not consists of loops in both the nodes.

- Only one node holds the loop. 

- One of the problems that are faced by the testers is of finding the simple paths. 

- This problem can be overcome by following a lower bound max- flow approach. 

- The simple path segments though being, are important in the data flow testing just like all the other path segments.