The MSC Bookstore hired you as a consultant to model a part of their information system, ordering a cap and gown for graduation for seniors. You will use data flow diagrams $($DFDs$),$ a tool utilized during the requirements structuring of the analysis phase, to model how data flows through this part of the MSC Bookstore$$s information system, the relationships among the data flows, and how data is stored at certain locations. DFDs also reveal the processes that change or transform data. DFDs are called process models since they focus on the movement of data between processes.

Requirements

After looking at your notes from several interviews with key staff and managers at the MSC Bookstore, as well as your own observations of the process of ordering a cap and gown for graduation, you summarized your findings as the following:

The order entry system of the bookstore takes order information from students, gives them a receipt, and then sends the cap and gown information to shipping $($the shipping department$).$

Specifically, a student places his$/$her order information. The system first validates this order information by obtaining an inventory status from the inventory file to make sure the ordered items are in$-$stock. $($Ignore here what happens if the items are out$-$of$-$stock.$)$ Once the order information is validated $($i$.$e$.$ there is correct order information; the items are in$-$stock, etc.$),$ the system then finalizes the order by giving a receipt to the student and sending the cap and gown information to shipping. Then the system updates the inventory file to reflect the changes resulting from the order.

$1.$Draw a context diagram, using pencil and paper.

What are your external entities and data flows?

$2.$ Draw a level$-0$ diagram, using pencil and paper.

What are your external entities, processes, data stores, and data flows?