What is DFD describe its level

What is DFD (Data Flow Diagram)

DFD is a designing concept used to transform a textual problem into pictorial or graphical form in a hierarchical order.

It describes how   data and information are transformed in a system in a pictorial manner.

DFD provides a complete description of:-

      (a) What data are processed?

       (b)  How processing is done?

(c)  What data are stored?

(d) Which stored data are used and

 (e)  Where the result flows?

DFD is top-down designing approach in which

(a)A high-level function is decomposed into a set of easy understandable function.

(b)Each function performed by system is analyzed and decomposed into more detailed description.

• A  DFD models a system by using external entities from which data flows to a process which transform the data  and creates output data flow which go to other processes or external entities or data stores .  From data stores, stored data may also flow to process as inputs.

Question:- Draw a DFD for universiy class management project

Objective/vision:our solution is supposed to automate the routine teaching-learning support activities so the academics authority can monitor it and control the things. It starts from Time-table generation on available resources like programmes, courses, subjects, teachers, lecture room/lab preferences. Assignments/lecture notes upload , Daily class attendance, student feedback, exams marks updation and students/faculty profile management would be the integral part of this system.

User of the System:                  

  A. End-user/students

  B. Data Manager

  C. Subject Teacher

  D. Admin/Dean/Director

Description for zero level DFD

• As stated in the question there are 4 users in the project.
• Here detailed informations regarding each student and teacher  are given and in response every student has got SIN(student identification num) or Roll No. and for teacher it is TIN(teacher identification num).
• Database Manager will perform all the data entry job.
• After giving routine generating command a routne will be generated. 

Admin can veiw the every user , his peformance and get the result by giving the query.                                                                                                                                                                                                         

 first  level DFD of university management:

Description of 1st level

every student , every teacher , evey class room and every subject should be  

 registerd

                                  Here  student_infodatastore contain information regarding student.

                                  Here  teacher_infodatastore contain information regarding teacher.

                                  Here  class_infodatastore contain information regarding class.

                                  Here subject_infodatastore contain information regarding