Part II: REA

RBS Tech Inc. is a business located in Newark. It purchases network devices from all around the world and resells them to customers. At present, RBS Tech Inc. processes its purchases manually and asks you to develop a database to help better process purchase data. You have conducted several interviews with employees. The following is a summary of your discussions.

RBS Tech Inc. has ten mangers, and each manager supervises at least one employee. One of managers of RBS Tech Inc. orders network devices online every Monday from a variety of suppliers. Suppliers generally deliver orders within two weeks. On arrival, one of employees checks each delivery against the order. In general, the employee receives each order in one delivery, but one delivery may include products that were ordered on two or more orders. Suppliers allow RBS Tech Inc. to pay for an order within 30 days, but all orders must be paid in full. An employee in the accounting deportment generally writes one check for each order, but may write a check to a supplier that covers several orders. RBS Tech Inc. has both a checking account and a savings account at NJ State Bank, and the checking account is used for payments.

(Note: If the business rules are not clear, use typical cardinalities. You also need to show the relationship between manager and employee in your REA diagram.)

Based on the above narrative description, create a REA diagram.

Hints:

Resources: Inventory and Cash

Events: Purchase Order, Receive Goods, and Pay Cash

Agents: Manager, Supplier, and Employee

Part III: DFD

Since opening its doors in Newark five years ago, RBS Tech Inc. has enjoyed tremendous success. To keep up with the strong demand for network devices in New Jersey, RBS Tech Inc. is expanding its operations. At the heart of the expansion is the introduction of a new Web-based acquisition system to handle the tremendous increase in purchases. You have conducted several interviews with employees who will interact with the Web-based acquisition system. The following is a summary of your discussions.

When an employee completes a purchase requisition form on the companys Web site, the system (i.e., Web-based acquisition system) receives the purchase requisition and prepares a purchase order using the information in the employee, supplier, and inventory files. The system also updates the purchase order file and sends the purchase order to a supplier via email. Once the supplier receives the purchase order, he or she checks the order and returns a supplier acknowledgment to the system via email, indicating receipt of the purchase order. Whenever the system receives the supplier acknowledgment, it generates a purchase order notification for further process. When the supplier ships goods, he or she also sends an invoice to the system via email. When the warehouse department accepts goods (shipped by the supplier), the department transfers a receiving report to the system. The system then matches the invoices with the purchase order notification and the receiving report and updates the accounts payable master file. The system also generates a payment authorization. Finally, based on the payment authorization, a payment (i.e., check) is made to the supplier, and the system automatically updates the accounts payable file.

Based on the following narrative description, create a context diagram and a Level-0 DFD.

Context Diagram

Hint:

Source/Destination Employee, Warehouse department, and Supplier

Level-0 DFD

Hints:

Main functions 1) Prepare and update purchase order, 2) Prepare purchase order notification, 3) Match and update accounts payable, and 4) Pay supplier

Data Store Employee file, Supplier file, Inventory file, Purchase order file, and Accounts payable file