Detailed Design Document (Modify Order)

Modifying an order is described in the above diagram. The user passes the order information to the system. The order corresponding to this information is retrieved from the Order datastore and modified to reflect the user's inputted information. The instance is then written back into the datastore.

Orders may only be modified before they have been filled. After a purchase order has been filled, no user may change the purchase order. This includes both the Administrators and Salespeople. This functionality, or lack of, is used to ensure the integrity of the data.

The returned status corresponds to the success of the operation. If the order is successfully modified and updated in the datastore, the status returns Successful. If the order can't be updated, the corresponding error message is returned.

P-Spec

Process ID	1.C.3
Process Name	Modify Order
Inputs	order info
Outputs	order info
Permissible User	Administrator, Salesperson
Assumptions	All information entered is syntactically correct.
Error Conditions	The Purchase order number entered does not exist. The Customer ID entered does not exist. The User ID entered does not exist. Product specified by product number and motif number does not exit Quantity ordered exceed allowable limit Order has been filled Successful

Data Elements (Data Dictionary)

Name	order
Kind	Data movement in DFD
Type	Instance of an Entity
Description	This data element corresponds to a complete instance of the Entity Order.

Name	order info
Kind	Data movement in DFD
Type	Multiple Field User Input
Description	These fields are input values from the User. They correspond to the fields in the Entity Order. Not all fields in the Order data table are necessarily present in an instance of the order information.

Name	status
Kind	Data movement in DFD
Type	Return Message
Description	This data element corresponds to an error message being returned from an operation. An error message may be both successful and unsuccessful. Unsuccessful error messages are further subcategorized into different errors based on the possible errors that can occur in an operation.