What are the different design and procedural aspects of Computerised Information System (CIS)?
The development of Computerised Information Systems (CIS) will generally result in design and procedural characteristics that are different from those found in manual systems. These different design and procedural aspects of CIS are-
(i) Consistency of Performance: Computerised Information Systems (CIS) perform functions exactly as programmed and are potentially more reliable than manual systems, provided that all transaction type and conditions that could occur are anticipated and incorporated into the system.
(ii) Programmed Control Procedures: The nature of computer processing allows the design of internal control procedures in computer programs. These procedures can be designed to provide controls with limited visibility (e.g., protection of data against unauthorized access may be provided by passwords). Other procedures can be designed for use with manual intervention, such as review of reports printed for exception and error reporting, and reasonableness and limit checks of data.
(iii) Single Transaction Update of Multiple or Data Base Computer Files: A single input to the accounting system may automatically update all records associated with the transaction (e.g., shipment of goods documents may update the sales and customers accounts receivable files as well as the inventory file). Thus, an erroneous entry in such a system may create errors in various financial accounts.
(iv) Systems Generated Transactions: Certain transactions may be initiated by the Computerised Information System (CIS) itself without the need for an input document. The authorisation of such transactions may neither be supported by visible input documentation nor documented in the same way as transactions which are initiated outside the CIS (e.g., interest may be calculated and charged automatically to customers account balances on the basis of pre-authorized terms contained in a computer program).
(v) Vulnerability of Data and Programme Storage Media: Large volumes of data and the computer programs used to process such data may be stored on portable or fixed storage media, such as magnetic discs and tapes. These media are vulnerable to theft, or international or accidental destruction.