Input control procedures must ensure that every transaction to be processed is received, processed and recorded accurately and completely .
These controls should ensure that only valid and authorized data is input and that these transactions are processed only once.
In an integrated environment , output generated by one system is input for another system, therefore, edit checks, validations, and access controls of the system generating the output must be reviewed as input controls.
Signatures on batch forms - provide evidence of proper authorization
Online Access Controls
Source Documents - are forms used to record data. It may be a piece of paper or an image displayed for online data input. A well designed source document increases speed and accuracy of data recording, controls work flow, facilitates the preparation of machine readable data, and facilitates subsequent reference checking.
The control number follows sequentially and any control numbers out of sequence or duplicated are rejected or noted on an exception report for follow-up purposes.
For example, invoices are numbered sequentially. The day’s begin with 12001 and end with 15045. If any invoice larger than 15045 is encountered during processing, that invoice would be rejected as an invalid invoice number.
a widget manufacturer receives orders for no more than 20 widgets. If an order for 200 widgets is received, the computer program should be designed to display a warning indicating that the order appears unreasonable.
A field should always contain data and not zeros or blanks. A check of each byte of that field should be performed to determine that some form of data, not blanks or zeros, is present.
For example, the employee number field on a new employee record is kept blank. This is identified as a key field and the record would be rejected, with the request that the field be completed before the record is accepted for processing.
Processing Controls ensure the completeness and accuracy of accumulated data. They ensure that data on a file or in a database remains complete and accurate until changed as a result of authorized processing or modification routines.
The following are processing control techniques:
Manual Recalculations - A sample of transactions may be recalculated manually to ensure that processing is accomplishing the anticipated task.
Edit Check - is a program instruction or subroutine that tests for accurate, complete and valid input and updates in an operation.
Run-to-Run Totals - provide the ability to verify data values through the stages of application processing. Run-to-run total verification ensures that data read into the computer was accepted and then applied to the updating process.