ABSTRACT
This chapter discusses several system control tools and techniques that are commonly used in information systems. Regression testing is a technique that compares the results obtained when the system is being audited to the results obtained under normal condition. Parallel simulation involves testing both the live system and a simulated system with the same data. The objective of input controls is to screen out and correct bad data before they enter the system. The purpose of operational controls is to provide an early warning in the event of system malfunction. Data integrity is ensured by carefully controlling and managing data entry, data maintenance, and data access from the time the data first enter the system until they are of no further use. The key is building controls into the system rather than simply adding them on after the system is completed.
