Question

Which of the following data flow diagram (DFD) guidelines is correct?

a. include within the system context any entity that performs one or more information processing activities
b. read computer data stores from the process bubble that requires the data
c. include within the system context any entity in the system narrative
d. data flows should never go from higher- to lower-numbered bubbles

Answer 1

The correct guideline for a data flow diagram is to read computer data stores from the process bubble that requires the data.

Step-by-step explanation:

The correct guideline for a data flow diagram (DFD) is option b. The computer data stores should be read from the process bubble that requires the data.

For example, if a process bubble needs to access a customer's information stored in a database, the data flow would go from the process bubble to the database.

Option a is incorrect because entities that perform information processing activities should be included within the system context, not just any entity. Option c is also incorrect as any entity mentioned in the system narrative is not necessarily included within the system context. Option d is incorrect because data flows can go from higher- to lower-numbered bubbles if it represents a hierarchical relationship.