Question

Describe the common types of errors for DFD diagrams

Answer 1

The common types of errors are as follows:

1. Black holes- A particular processing step having input flows but no such output flows.

2. Grey holes- A particular processing step having outputs which are greater than the sum of the given inputs or in other words, the inputs failed to produce the expected output.

3. Miracles- A particular processing step that has output flows but no input flows.

Answer 2

Explanation:

There are mainly three common types of errors for DFD diagrams:

• Black holes - When there is input flow in a particular processing step and no output flow occurs, then this type of error is called Black Hole.
• Grey holes- When the outputs for a particular processing step are greater than the sum of given outputs then this type of error is called Grey Hole. Under this error, input fails to produce the expected output.
• Miracles- It is the reverse of the Black Hole error. There is output flow but no input flow is present for the particular processing step.