I am working on a problem regarding accounting information systems, the question is asking how to make a context DFD and physical DFD. the question is a customer uses his mobile application grub club to order food: The order entry process for GrubClub starts when a customer logs into the GrubClub phone app. To log in, customers input their username and password into their phone, and this information is then transmitted to GrubClub's server where it checked for validity.

After the server notifies the customer's phone that the login information was valid, the phone displays a request for the delivery address for where the customer wants their order to be delivered. The customer enters a delivery address which is sent to GrubClub's server. The GrubClub server uses a web service through Google that provides the GrubClub server with an estimate of the distance (in miles) between each restaurant and the customer's delivery address. Using this information, the GrubClub server looks through GrubClub's ERP to identify restaurants that are open and sufficiently close to the delivery address to fill the customer's order (note: assume that a store's status as open or closed is tracked by a different process) . The server then provides the customer with a list of the restaurants from which they can place an order. If there are no available restaurants, an error message is provided to the customer.

The customer can then browse through the list of restaurants. Once the customer selects a restaurant on their phone, that information is sent to the GrubClub server where the current menu (i.e. items and prices) for that restaurant is retrieved from GrubClub's ERP, sent to the customer's phone, and displayed for the customer. (Note: this process may repeat multiple times, if the customer browses menus; however, only show it happening once in your DFDs and SFC).

The customer then selects the items and quantities that they would like delivered. When done entering all items and quantities (note: you can show this as happening in one step), the customer selects the "checkout" option on the phone application. At this point, the order data is sent to GrubClub's server. The server then verifies the restaurant status (i.e. open or closed). If the restaurant closed while the customer was preparing their order, an error message is sent to the customer's phone where it is displayed for the customer. If no error occurs, a customer order that summarizes the restaurant, items, quantities, prices, tax, delivery charge, and expected time to delivery is prepared by the GrubClub server. To prepare the customer order, the GrubClub server accesses the restaurants table in the ERP database to find the average meal prep time (in minutes) for the restaurant that the customer ordered from. It also uses a web service provided by Google to estimate the average trip length (in minutes) for an automobile traveling from the restaurant to the delivery address. The GrubClub server records the customer order before sending it to the customer's phone where it is displayed for the customer.

At this point, the customer reviews the order for accuracy before inputting their credit card information (number, expiration date, and security code), billing address, and phone number to complete the order. This information is then sent to the GrubClub server, which in turn sends the credit card information and order total to a credit company. If the transaction is approved, the credit card company sends an authorization number to GrubClub's server, which then updates the customer order record and sends a confirmation number to the customer's phone where it is displayed for the customer along with the estimated time to delivery.

To finish the process, the customer order information is sent to the appropriate restaurant for order fulfillment and delivery.