Input Controls
Document design
A well-designed document is easy to logically follow, allowing for it to be completed or reviewed more quickly. Further, the logical flow of information primes human attention, reducing the number of inaccuracies.
Check digit
Calculates a digit that is computed from other digits. For example, a 9-digit inventory item would calculate a 10th digit based on the original 9-digits. The 10thdigit would then be appended to the original nine digits to form a complete 10-digit number.
Batch totals
Calculates the numeric values for a batch of input records
Closed-loop verification
Checks the accuracy of input data by using it to retrieve and display other related information. For example, if a clerk enters an account number, the system should retrieve the corresponding account name to verify that the correct account number has been entered.
Validity check
Compares the ID code or account number in transaction data with similar data in the master file to verify the account exists. For example, if Customer 1234 wants to place an order, they must already exist within the Customer Master Data File with other pre-approved customers.
Reasonableness check
Determines the correctness of the logical relationship between two data items. For example, it is illogical that a student scores 750 points on an exam worth 100 points.
Sequence check
Determines whether a transaction file is in the proper numerical or alphabetical sequence.
Field check
Determines whether the characters in the field are the proper type. For example, a U.S. zip code would not contain any alphabetic characters, only numbers.
Sign check
Determines whether the data in the field has the appropriate sign. For example, time should never be negative.
Size check
Ensures that the input data will fit into the assigned field.
Turnaround document
Improve accuracy by eliminating the potential for input errors when entering data manually. This control is nested under document design.
Hash total
Nonfinancial numeric field, such as the total of the quantity-ordered field in a batch of sales transactions.
Prenumbered documents
Prenumbering documents makes it possible to verify that no documents are missing. Should be able to identify missing or duplicate source documents. This control is nested under document design.
Approvals
Some purchases or other processes require special authorization. An approval can be performed either manually or automatically by comparing one or more criteria to the fixed values for an observation (e.g., a credit manager/sales server approving an order by referencing the customers' credit limit).
Financial total
Sums a field that contains monetary values, such as the total dollar amount of all sales for a batch of sales transactions.
Prompting
System requests each input data item and waits for an acceptable response, ensuring all necessary data are entered. This is an example of an online completeness check.
Limit check
Tests the numerical amount against a fixed value. For example, regular hours worked for an hourly employee must be less than or equal to 40. Any excess would be entered into a separate overtime field.
Range check
Tests whether a numerical amount falls between predetermined lower and upper limits. For example, may target a marketing campaign to individuals within a certain income range.
Preformatted screens
Used for manual data entry into an information system. Preformatted screens clearly label fields and usually follow the logical flow of their analog (physical) counterparts. Preformatted screens structure the data entry process, can automatically populate fields, and prevent errors.
Completeness check
Verifies that all required data items have been entered. For example, an order will not be processed unless you include your billing address. Can also be referred to as an input acceptance check.
