42 terms

ISYS 414 Chapter 10

Vocab for AIS Chapter 10.
turnaround document
Records of company data sent to an external party and then returned to the system as input. Prepared in machine-readable form to facilitate their subsequent processing as input records.
field check
An edit check in which the character in a field are examined to ensure they are of the correct field type (e.g., numberic data in numeric fields).
sign check
An edit check that verifies that the data in a field have the appropriate arithmetic sign.
limit check
An edit check to ensure that a numerical amount in a record does not exceed some predetermined limit.
range check
An edit check designed to verify that a data item falls within a certain predetermined range of acceptable values.
size check
An edit check that ensures the input data will fit into the assigned field.
completeness check
An online data entry control in which the computer determines whether all data required for a particular transaction have been entered.
validity check
An edit test in which an identification number or transaction code is compared with a table of valid identification numbers or codes maintained in computer memory.
reasonableness test
An edit check of the logical correctness of relationships among data items. For example, a journal entry that debits inventory and credits wages payable is not reasonable.
check digit
ID numbers (such as employee number) can contain this, which is computed from the other digits. For example, the system could assign employees a nine-digit number, calculate a tenth digit from the nine, and append it to form a ten-digit number.
check digit verification
Recalculating a check digit to verify that an error has not been made. This calculation can be made only on a data item that has a check digit.
sequence check
An edit check that determines if a batch of input data is in the proper numerical or alphabetical sequence.
batch totals
The sum of a numerical item for a batch of documents. These totals are calculated prior to processing the batch and are compared with machine-generated totals at each subsequent processing step to verify that the data was processed correctly.
financial total
The total of a dollar field, such as total sales, in a set of records. It is usually generated manually from source documents
hash total
A total generate from values for a field that would not usually be totaled, such as customer account numbers. It is usually generated manually from source documents prior to input and compared with machine-generated totals at each subsequent processing step. Any discrepancy may indicate a loss of records or errors in data transcription or processing.
record count
A total of the number of input documents in a process or the number of records processed at a given time.
An online data entry control that uses the computer to control the data entry process. The system request each required item of input data and then waits for an acceptable response before requesting the next required item.
closed-loop verification
An input validation method that uses data entered into the system to retrieve and display other related information so the accuracy of the input data can be verified.
header record
Type of internal label that appears at the beginning of each file and contains the file name, expiration date, and other file identification information.
trailer record
Type of internal label that appears at the end of each file and serves as an indicator that the end of the file has been reached. The trailer label contains the batch totals calculated during input.
transposition error
An error that results when numbers in two adjacent columns are inadvertently exchanged (for example, 64 is written as 46).
cross-footing balance test
A procedure in which worksheet data are totaled both across and down. Then the total of the horizontal totals is compared to the total of the vertical totals to ensure that the worksheet balances.
zero-balance test
An internal check that requires the balance of an account to be zero after all entries to it have been made.
concurrent update controls
Controls that prevent multiple users from updating the same record simultaneously.
When data are transmitted, the sending device can calculate a hash of the file. The receiving device performs the same calculation and sends the result to the sending device.
parity bit
An extra bit added to a byte and magnetized as needed to ensure that there is always an odd (or even) number of magnetized bits. The computer uses the odd (or even) parity scheme to check the accuracy of each item of data.
parity checking
Process in which a computer, as it reads or receives a set of characters, verifies that the proper number of magnetized bits is in each characters received. If not, the corresponding character may contain an error.
fault tolerance
The capability of a system to continue performing when there is a hardware failure.
redundant arrays of independent drives (RAID)
Writing data to multiple disk drives simultaneously so that if one disk drive fails the data can be readily accessed from another.
uninterruptible power supply (UPS)
An alternative power supply device that protects against the loss of power and fluctuations in the power level by using battery power to enable the system to operate long enough to back up critical data and safely shut down.
A copy of a database, file, or software program.
recovery point objective (RPO)
The length of time between the last backup and the time that an incident occurred. It represents the period of time for which management is willing to have to reenter data about past transactions.
recovery time objective (RTO)
The time by which the organization's information system must be available again following a disaster.
real-time mirroring
Maintaining two copies of the database at two separate data centers at all times and updating both copies in real-time as each transaction occurs.
incremental backup
Copying data items that have changed since the last backup. This produces a set of incremental backup files, each containing the results of one day's transactions.
differential backup
Copying all changes made since the last full backup. Thus, each new differential backup file contains the cumulative effects of all activity since the last full backup.
A copy of a database, master file, or software that is retained indefinitely as a historical record, usually to satisfy legal and regulatory requirements.
disaster recovery plan (DRP)
A plan to recover data processing capacity as smoothly and quickly as possible in the event of an emergency that disables the computer system.
cold site
A location that provides everything necessary to quickly install computer equipment in the event of a disaster.
hot site
Completely operational facility configured to meet the user's requirement that can be made available to a disaster-stricken organization on short notice.
business continuity plan (BCP)
A plan that specifies how to resume all business processes in the event of a major calamity.
change control
The process that ensures that hardware, software, or process modifications do not reduce systems reliability.