Detailed Data Flow diagrams or level 1 DFD (Part 3)

Once context of a system has been captured using context level diagram, the analyst would expand his activities and start digging out system’s internal details. Therefore, the same context level diagram is further expanded to include all major processes of the system that make up system functionality. So, instead of portraying system as a black box entity, the analyst would add processes that deal with the external agents and produces certain outputs. This is level one of a data flow model.

In part 2 we draw the Context Level or level 0 DFD, as shown the figure below: now we further expend this diagram and drawn the Level 1 Data Flow Model.

1. First of all we expend the activities of Administrator, as shown the diagram given below:

Here we explain the activities of Administrator, Administrator will manage the user accounts, and record the data. Administrator is manage the FAQ, Administrator will generate the survey, generate the reports, and Administrator have right to synchronize the local database with main database and also maintain the both databases. 

2. Second we expend the activities of Unregistered Users, as shown the diagram given below:

Unregistered User will create a new account or use the FAQ services of the application. Once it will create the new account, its information will save in record,

3. Now we further expend the activities of Registered Users, as shown the below diagram:

Registered user will do the following tasks:
   a.  Registered user will use the desktop interface as well as web interface of application.
   b.  It will also generate the survey.
   c.  It will generate the different kind of reports.
   d.  It will use the FAQ services.
   e.  Through web interface it will synchronize the local database to main database.