The Meyers Pharmaceutical Company has the following system for billing and recording accounts receivable:
1. An incoming customer's purchase order is received in the order department by a clerk who prepares a prenumbered company sales order on which the pertinent information, such as the customer's name and address, customer's account number, and items and quantities ordered, is inserted. After the sales order has been prepared, the customer's purchase order is stapled to it.
2. The sales order is then passed to the credit department for credit approval. Rough approximations of the billing values of the orders are made in the credit department for those accounts on which credit limitations are imposed. After investigation, approval of credit is noted on the sales order.
3. Next the sales order is passed to the billing department, where a clerk key-enters the sales order information onto a data file, including unit sales prices obtained from an approved price list. The data file is used to prepare sales invoices.
The billing application automatically accumulates daily totals of customer account numbers and invoice amounts to provide "hash" totals and control amounts. These totals, which are inserted in a daily record book, serve as predetermined batch totals for verification of computer inputs. The billing is done on prenumbered, continuous, multi-copy forms that have the following designations:
(a) Customer copy
(b) Sales department copy, for information purposes
(c) File copy
(d) Shipping department copy, which serves as a shipping order Bills of lading are also prepared as by-products of the invoicing procedure.
4. The shipping department copy of the invoice and the bills of lading are then sent to the shipping department. After the order has been shipped, copies of the bill of lading are returned to the billing department. The shipping department copy of the invoice is filed in the shipping department.
5. In the billing department, one copy of the bill of lading is attached to the customer's copy of the invoice and both are mailed to the customer. The other copy of the bill of lading, together with the sales order is then stapled to the invoice file copy and filed in invoice numerical order.
6. The data file is updated for shipments that are different from those billed earlier.
After these changes are made, the file is used to prepare a sales journal in sales invoice order and to update the accounts receivable master file. Daily totals are printed to match the control totals prepared earlier. These totals are compared with the "hash" and control totals by an independent person.

Required
a. Identify the important controls and related sales transaction-related audit objectives.
b. List the procedures that a CPA will use in an audit of sales transactions to test the identified controls and the substantive aspects of the sales transactions.