Charlie's Computer Repair Services, LLC (CCRS) is a limited liability company that provides computer repair services to customers. These repair services may involve just labor (e.g. resolving a hardware device conflict) or may involve replacing parts. CCRS stocks a supply of spare parts to use in its repairs. CCRS offers many different types of repair services, and a customer's repair service engagement may reflect more than one type. For example, a customer may request to have a monitor repaired and a hard disk replaced at the same time. However, if the customer has more than one computer to be repaired, repairs on the separate computers must be written up on different invoices. For example, if a customer brought in a desktop computer and a laptop computer, all repairs made to the desktop computer would be reflected on one invoice, and all repairs made to the laptop computer would be reflected on a second invoice. CCRS's repair people specialize in different types of service, therefore more than one employee may need to participate in a repair service engagement. For example, employees Jim and Sarah both specialize in video/monitor problems. Jamie, Emily, or Dale can handle problems with disk drives (hard or floppy). CCRS has several sales clerks who are responsible for bringing in repair service engagements, and for processing the resulting cash receipts. These sales clerks are not assigned to particular customers, and they never work together to accomplish a transaction. Customers are required to make a deposit of 50% of the estimated charges before the repair services are begun. The customers are required to pay the balance of the bill before they can retrieve their computer(s). All cash receipts for a particular day are deposited into one of several bank accounts owned by CCRS; which account they are deposited into rotates from day to day. NOTE: CCRS has specifically requested to keep repair people and sales clerks in separate tables (i.e., do NOT make one combined employee table).
Required: Prepare a business process level REA model with entities, relationships, cardinalities, and attributes. Use all the attributes in the following list in your model; do not add or subtract any attributes. If any of the attributes are derivable, describe how they can be derived and note whether they are static or volatile derivable attributes.