I am currently preparing DFD(Data Flow Diagrams) for my project which is a Job Portal. Now on the Company Side there is an option in the home page menu "Jobs Posted". After clicking on it all the jobs posted by the Company are shown on next page. Every job post has 4 options (Edit, Delete, Post Details and Applicant List). The "Applicant List" option redirects to the next page where all the lists of applicants for that particular job post are shown.
I am confused about what will go in 1st level DFD and what will be there in 2nd level DFD. And will I also have to make a 3rd level DFD. Can someone tell me how do I distribute the process in DFD?
I have tried to make DFD for this but it is still confusing about what will go where.
The data flow diagram is meant to present the flow of data between processes/systems/modules. It is not meant to model the navigation between web pages, since each page may receive data from the previous page, but also from the user and the database. This results in cluttered diagrams that do not make the flow very understandable.
I therefore recommend to consider wireframes to model the user navigation/flow across the pages in a very expressive way, and keep the DFD for the real process (not one per page, but one for a group of related pages).
Now if you'd really want to use DFD for your purpose, you'd go per functional decomposition. You would use the 1st level to show the interaction between the application, the user and the database. The second level would be used to show the flow between your main components e.g. menu, job posting management, job applicant management, etc... The third level would then zoom into these functions and show the data flow between the different parts of of one of the main components (i.e. could be the different related pages.