Hero Ltd is using an AIS developed by its IT department. Recently,

an internal IT auditor reviewed the accounts receivable subsystem and

discovered that more than 50 customer accounts with balances between

$2,000 to $5,000 each could not be traced to the name and address of

the customers. The IT auditor found that the addresses were all blank. In

addition, the customer contact phone numbers all shown as '00000000'.

The IT auditor also found that there were no credit applications on file

for this group of customers. These customers' payments were overdue

for more than 18 months. However, the accounts receivable aging

reports failed to show these customers.

After the IT auditor reported the findings to the audit committee,

the audit committee ordered for a full investigation immediately.

Coincidentally, on the first day of the full investigation, a salesman and

a computer operator did not report to duty and both of them could not

be traced.

Required:

aExplain in detail how the fraud could have been committed.

(15 marks)

bExplain in detail three important programme change controls that

should be implemented at Hero Ltd.