please answer the following job interview question Without d

please answer the following job interview question.

Without dataflow diagrams, it is not possible to create data flow testing graphs.

Do you agree? Please explain why you agree or why you disagree.

Solution

Solution:-

Without dataflow diagrams, it is not possible to create data flow testing graphs. It is quite right statement and I am agree with this. Because Data flow diagram is a strong representation of Flow of data, Data storage and the overview of the process of system. So when we go to data flow Testing then we need to have a system data flow diagram to understand the data inputs and outputs, storage of data and the relationship of external entities and system process. After we understand the whole system process overview and flow of data, we can design a data flow Testing graphs.

Data flow testing is a family of test strategies based on selecting paths through the program\'s control flow in order to explore sequences of events related to the status of variables or data objects. Dataflow Testing focuses on the points at which variables receive values and the points at which these values are used. Data flow testings graph based on Flow of data and helps us to pinpoint any of the following issues:

A variable that is declared but never used within the program.

A variable that is used but never declared.

A variable that is defined multiple times before it is used.

Deallocating a variable before it is used.

Here we discuss about data flow diagram and data flow testing graphs with a little bit details.

Data flow diagram is an overview of a system. It represents the flow of data in the system. It is an initial representation of data flow in a system, from where data coming and where stored. It shows the process which followed by a system.

A data-flow diagram is a graphical representation of the \"flow\" of data through an information system. DFDs can also be used for the visualization of data processing.

The DFD lets you visualize how the system operates, what the system accomplishes and how it will be implemented, when it is refined with further specification. A data flow diagram is strong in illustrating the relationship of processes, data stores and external entities in business information system.

On a DFD, data items flow from an external data source or an internal data store to an internal data store or an external data sink, via an internal process.

It simply doesn\'t contain any information about control flow. The timing of operation, Data dependency, data validation, Flow of control, sequence of processes, these type of information doesn\'t described in data flow diagram. This information is described in control flow diagrams.

Now we discuss about data flow testing graph. Data flow testing is a technique used to detect improper use of data in a program. By looking data usage, risky areas of code can be found and more test cases can be applied.To test data flow we devise control flow graph. A data-flow graph (DFG) is a graph which represents data dependencies between a number of operations.

Data flow testing graphs checks for the anomalies related to data types, Data dependency, data processing and control flow.

To create a Data flow testing graph it is required to know about the data flow in system and process of the system. Inputs, outputs and storage of data so it can be possible to check data dependency, types of data and flow of control during the process.

So we can say that it is not possible to create data flow testing graphs without Data flow diagrams.