What control or controls would you recommend in a computer processing system to prevent the following situations?
a. Working through the main control console, the night- shift computer operator made a change in a payroll program to alter the rate of pay in his favor.
b. A customer payment recorded on a remittance advice as $ 55.05 was entered into the computer from a data terminal as $ 550.50.
c. A new program to process accounts receivable was unreliable and would not handle common exceptions. The programmer who wrote the program recently quit the organization because he was repeatedly asked to document this program (which he never did do).
d. The payroll master file was loaded incorrectly on a disk drive that was supposed to hold the accounts receivable master file. The accounts receivable program was nevertheless run, destroying the payroll master file.
e. A weekly payroll check issued to an hourly employee was based on 96 hours rather than 46.
f. The master inventory file, contained on a removable magnetic disk, was destroyed by a small fire next to the area where it was stored. The company had to take a special complete inventory to reestablish the file.
g. The magnetic tape containing accounts receivable trans-actions could not be located. A data processing supervisor said that it could have been put among the scratch tapes available for use in processing.
h. In preparing payroll checks, the computer omitted 12 of a total of 1,570 checks that should have been processed. The error was not detected until the supervisors distributed the checks.
i. A sales transaction document was coded with an invalid customer account code (seven digits rather than eight). The error was not detected until the updating run, when it was found that there was no such account to which the transaction could be posted.
j. During data entry of customer payments, the digit 0 in a payment of $ 123.40 was mistakenly entered as the letter O. As a result, the transaction was not processed correctly.
k. A systems analyst entered a special routine one evening after work. The next day she obtained the program that calculates interest payments on customer accounts and processed it to add her routine to the program’s logic. Her routine adds the fraction of a cent of each customer’s interest, which otherwise would be rounded off, to her own account at the bank.
l. A salesman entering a customer order from a portable data entry terminal entered an incorrect but valid product number. As a result, the customer received a delivery of 100,000 kilograms of industrial salt rather than industrial sugar.
m. A customer called to inquire as to why he received a bill for 5 cents amount due when postage cost much more than that amount.