Information System Control

Information System Control

Information system controls are methods and devices that attempt to ensure the accuracy, validity and propriety of information system activities. It is design to monitor and maintain the quality and security of the input, processing, output, and storage activities of any information system.

Input control

Example include password and other security codes, formatted data entry screen, audible error signals, templates over the keys of keys-driven input devices, and prerecorded and prenumbered forms. Input of source documents can also be controlled by registering them in a logbook when they are received by data entry personnel. Real-time system that use direct access files frequently recorded all entries into the system on magnetic tape control logs that preserve evidence of all system inputs. Computer software can include instruction to identify incorrect, invalid, or improper input data as it enters the computer system. For example, a data entry program can check for invalid codes, data fields, and transactions. Also, the computer can be programmed to conduct ‘reasonableness checks’ to determine if input data exceed certain specific limits or are out or sequence. This includes the calculation and monitoring of selection control totals.

Data entry and other system activities are frequently monitored by the use of control totals. For example, a record count is a control total that consists of counting the number of sources documents or other input preparation. If the forms of control do not match, a mistake has been made. Batch totals and hash totals are other batch of transactions, such as the sales documents in a batch of sales transactions. Hash totals are the sum of data fields hat are added together f...

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...ural and man-made disasters do happen. Hurricanes, earthquakes, fires, floods, criminals and terrorist act and human error can all severely damage an organization’s computing resources. Many firms could survive only a few days without computing facilities. That’s why organizations develop disaster recovery procedures and formalize them in a disaster recovery plan. It specific which employees will participate in disaster recovery and what their duties will be; what hardware, software, and facilities will be used; and the priority of applications that will be processed. Arrange with other companies for use of alternative facilities as a disaster recovery site and offsite storage of an organization’s databases are also part of an effective disaster recovery effort.

Works Cited

James A.O’Brien (1997) Introduction to Information System. Eight ed. New York: Tom Casson