The accounts receivable update program posts to accounts receivable by sequentially matching the
Account Number key in each sales order record with the corresponding record in the AR-SUB
master file. This procedure creates a new AR-SUB master file that incorporates
all the changes to the customer accounts that are affected by transaction records. The
original AR-SUB master file remains complete and unchanged by the process. The creation
of a new and separate master file is a characteristic of sequential file processing.
A side benefit of this is the automatic creation of a backup version of the file being
updated. Figure 9.2 illustrates this method with some sample records.
Each sales transaction record processed is added to the sales journal file. At the end
of the run, these are summarized and an entry is made to the journal voucher file to
reflect total sales and total increases to accounts receivable.
To spread the billing task evenly over the month, some firms employ cycle billing
of their customers. The update program searches the billing date field in the AR-SUB
master file for those customers to be billed on that day of the month and prepares statements
for the selected accounts. The statements are then mailed to the customer.