The document describes a food ordering system using data flow diagrams (DFDs) at multiple levels. A context DFD shows the food ordering system process interacting with external entities like customers, suppliers, the kitchen, and managers. A level 1 DFD breaks down the food ordering system process into sub-processes like order entry, delivery, and management reporting. A level 2 DFD further expands on the management reporting process, showing how it aggregates data on sold items and inventory to generate a report for restaurant managers.

4. 1
Food ordering system
customer
supplier
kitchen
manager
Context diagram :- The figure below shows a context Data Flow Diagram that is drawn for a Food
Ordering System. It contains a process (shape) that represents the system to model, in this case, the
"Food Ordering System". It also shows the participants who will interact with the system, called the
external entities. In this example, the Supplier, Kitchen, Manager, and Customer are the entities who
will interact with the system. In between the process and the external entities, there is data flow
(connectors) that indicate the existence of information exchange between the entities and the
system

5. Level 1:-
The figure below shows the level 1 DFD, which is the decomposition (i.e. break
down) of the Food Ordering System process shown in the context DFD. Read
through the diagram and then we will introduce some of the key concepts based
on this diagram.

6. Level 2 diagram More detailed information about the activity of the “Generate Management Report” is
given at this level of DFD. Having access to data of sold items and data of inventory should be available for
generating the report of management. Then, both data of solid items and data of inventory need to be
aggregated after which the restaurant manager should get the report of management that is prepared from the
above calculations.The above details are shown below