Input Control - Auditing in EDP

Input Control : 

Input Control and its TYPES

INPUT CONTROLS : 

INPUT CONTROLS Designed to provide reasonable assurance that the data submitted for processing are complete, properly authorized and accurately translated into machine readable form.

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TYPES OF INPUT CONTROLS

Limit Check : 

Limit Check Limit checks are used to identify field values that exceed an authorized limit Ensures that only data within predetermined limits will be entered into and accepted by the system rate per hour cannot be lower than the minimum set by law or higher than the maximum set by management (Assume that the firm’s policy is that no employee works for more than 44 hours per week)

Range Check : 

Range Check Imposing upper and lower limits to the acceptable values of data If the range of pay rates for hourly employees in a firm is between 8 and 20 dollars, the control can examine the pay rate field of all payroll records to ensure that they fall within this range.

Numeric Check : 

Numeric Check Ensures that only numbers are entered into and accepted by the system where only numbers are required to be entered. A customer’s account balance should not contain alphabetic data and the presence of it will cause a data processing error.

Alphabetic Check : 

Alphabetic Check Ensures that letters are entered into and accepted by the system where only letters are required to be entered. A person’s name should only include letters from A-Z so that it would not be an error.

Validity Check : 

Validity Check A validity check compares actual field values against known acceptable values. This control is used to verify such things as transaction codes, state abbreviations, or employee job skill codes. If the value in the field does not match one of the acceptable values, the record is flagged as an error (authorized employee account numbers)

Field Check : 

Field Check Ensures that the input data agree with the required field format All SSS number must contain ten digits for it not to be rejected by the computer.

Password : 

Password Ensures that the operator is authorized to access computer programs and files The password must contain a minimum of one lower case character, one upper case character, and one digit or special character to be secured.

Data Check : 

Data Check Ensures that no blanks will be entered into and accepted by the system when data should be present. An “S’’ or “M’’ is entered in response to single or married

Missing Data Check : 

Missing Data Check Some programming languages are restrictive as to the justification (right or left) of data within the field. If data are not properly justified or if a character is missing (has been replaced with a blank), the value in the field will be improperly processed. In some cases, the presence of blanks in numeric data field may cause a system failure. When the control routine detects a blank where it expects to see a data value, the error is flagged.

Special Character Check : 

Special Character Check Ensures that only specific special characters are entered into and accepted by the system where only these special characters are required to be entered Dashes in account numbers, cell/telephone numbers, SSS numbers, etc.

Self-checking Digit : 

Self-checking Digit Data codes are used extensively in transaction processing systems for representing such things as customer accounts, items of inventory, and general ledger accounts in the chart of accounts. If the data code of a particular transaction is entered incorrectly and goes undetected, then a transaction processing error will occur, such as posting to the wrong account.

Self-checking Digit : 

Self-checking Digit Two common classes of data input errors A. Transcription errors 1. Addition errors - occur when an extra digit or character is added to the code e.g., inventory item number 83276 is recorded as 832766

Self-checking Digit : 

Self-checking Digit 2. Truncation errors - occur when a digit or character is removed from the end of a code. e.g., in this type of error, the inventory item above would be recorded as 8327 3. Substitution errors - are the replacement of one digit in a code with another e.g., code number 83276 is recorded as 83266

Self-checking Digit : 

Self-checking Digit B. Transposition errors 1. Single transposition error - occur when two adjacent digits are reversed. e.g., for instance, 83276 is recorded as 38276 2. Multiple transposition errors - occur when nonadjacent digits are transposed e.g., 83276 is recorded as 87236