Tutorial on How to draw Data Flow Diagram – Train and Air Ticket Reservation System – Example

Train and Air Ticket Reservation System – Data Flow Diagram – Example

Train Ticket reservation system is a very complicated system. It is complicated because it consists of more number of entities and processes. Data in this system should be collected from more number of entities and need to be processed within more number of processes. Example of this type of system is explained below:


This Train Ticket Reservation System consists of four external entities; namely Customer, Vendor, Schedule manager and Train representative. Customer are the one who issue for the tickets, Vendor are the counterman who receives payment to handover tickets to the customer, Schedule manager manages the time schedules of train with accordance to the route and Train Representative monitors the overall activities on the system like the seats capability and passenger facility. These four entities are governed by the single or multiple processes through the flow of data.

This Data Flow Diagram was taken directly from my notes so if you have any problems in understanding it, you are kindly requested to leave comment below.

The standard of naming process-name is; process name should be action verb that specifies the operation(see on: How do we begin to construct Data Flow Diagrams? ). Advantage of preparing this DFD can be; proper knowledge of Data flow, effects of external entities in the system, determination of process in the overall system.

The table below shows the data attributes by the corresponding entity:

Entity Outgoing Data Attributes Incoming Data Attributes
Customer C_name, Route, Prefered_date, payment, seat_prefered Tickets, Time_of_departure
Vendor Tickets C_name, Route, Prefered_date, Payment
Schedule Manager Departure_time, Routes Routes, Prefered_date
Train Representative Seat_no Seat_prefered

In the context diagram of DFD; general symbols of DFD are used to prepare a simple model. Four different entities are bounded by the dataflow with the process Ticket Reservation. Whenever a customer needs tickets then he gives his information and pays for the ticket, vendor with the information from schedule manager and train representative provides customer with tickets if available.

Train Ticket Reservation System; Context Diagram

Train Ticket Reservation System; Context Diagram

Figure: Train Ticket Reservation System; Context Diagram                   

Similarly, in Level 1 DFD entities are same but process is broken down into other sub processes which would help to clarify the system in better way. In this model, Ticket Reservation process is further divided into four respective processes; namely Reserve Ticket, Create Bills, Check Seats available and Check Schedule. Process name are given number as prefix. Besides processes there are three databases; namely tickets_db, bills_db and schedules_db for storage of tickets, bills and schedules respectively.

Train Ticket Reservation System; Level 1 DFD

Train Ticket Reservation System; Level 1 DFD

Figure: Train Ticket Reservation System; Level 1 DFD

All four processes do their different jobs and integrate to a system so as to reserve Train Tickets. From a successful run of the process finally a ticket can be reserved.

We hope by this DFD you are clear the method of reserving a ticket for train, now you can implement this idea onto your projects. This type of model will be very helpful for the projects like Train Ticket Reservation System, Air Ticket Reservation System and any other ticket reservation system.

Although this example was taken from one of my daily assessment, I hope this example will definitely help you in modeling your projects and assessments. You can also add other processes, entities, data attributes and data objects to make the system clearer and board. Find more of Examples of DFD here: Data Flow Diagram