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 his rate of pay in his favor.
-operator should not have access to program documentation (source code)
-use password
-console log should be reviewed for unauthorized activity
B. A customer payment recorded on a remittance advice as $55.05 was entered into the computer from a data terminal as $550.50.
-batch control totals
C. The magnetic tape containing accounts receivable transactions could not be located. A data processing supervisor said that it could have been put among the scratch tapes available for use in processing.
-external file labels
-file library
-enforce & review file access procedures & documentation
D. A customer called to inquire as to why he received a bill for five cents amount due, when postage cost is more than a quarter.
-limit check
E. 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. Oops……..
-combination field check
-product number matched with description—closed loop verification
F. 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 correctly processed.
-field check
-all characters are numeric
G. In preparing payroll checks, the computer omitted 12 of a total of 1570 checks that should have been processed. The error was not detected until the supervisors distributed the checks.
-batch control totals
-sequence check
H. The master inventory file, contained on a removable magnetic disk, was destroyed by a small fire