AIS - CHAPTER 4

THE DATA PROCESSING CYCLE

Overview

• Data Processing Cycle - the operations performed on data in a computer-based system to produce information.



• Accountant's role - to interact with systems analysts to answer basic questions:

1. What data is entered and stored?
2. Who should have access to the data?
3. Which data storage approach should be used?
4. How should data be organized, updated, stored, accessed and retrieved?
5. How can information needs be met?

Data Input

• Defined - data captured and converted to machine readable form



• May require preparation

1. Classification - assigning codes
2. Verification - ensure data accuracy at the time of entry
3. Transmittal - one location to another

• Data capture

1. Source documents
2. Turnaround documents - output returns to system as input
3. Keying to online terminals with prompting
4. Source data automation - capture data in machine readable form

Data Storage - important resource

• Terminology

• entity - something about which data is stored

1. attributes - characteristics in an entity
2. characters - numbers or letters
3. Data value - characters combined in a meaningful way

• Data storage hierarchy

1. Field - data values stored in a physical space
2. Record - fields grouped together
3. File - grouping of related records
4. Data base - files containing related data

• Types of files

1. Master - all data about an item of interest
2. Transaction - group of similar transactions for processing
3. Table - reference data used during processing
4. History - transactions already processed
5. Backup - duplicate copy of current file
6. Suspense - records temporarily removed for correction
7. Report - temporary awaiting printing at a later time

Data Base Approach

• Views data as an organizational resource



• Data Base Management System (DBMS) - program that manages and controls data and interfaces between data and applications



• DB Administrator (DBA) - person responsible for data base



• Data warehouse - very large enterprise data base



• Logical and Physical Views of Data

1. Logical - how users conceptually understand data relationships
2. Physical - how data is physically arranged and stored on media
3. Logical and Physical are independent - one can be changed without changing the other.

• Advantages of DB

1. Data integration - unlimited combinations of information
2. Report flexibility - easily revised reports and queries
3. Minimal redundancy and inconsistency - data stored once
4. Data independence - data and programs are independent
5. Central mgt of data - DBA in control
6. Security - DBMS has built-in controls such as passwords
7. Cross-functional analysis - relationships across functional areas

• How DB technology is used

1. Internal data bases - created to gain competitive advantage
2. External data bases - sell information to customers.

Data Processing

• Data maintenance

1. Additions/deletions
2. Updates
3. Changes

• Data processing

1. Calculating
2. Comparing
3. Summarizing
4. Filtration
5. Retrieval

• Keys - identifier for records

1. Primary - unique to each record
2. Secondary - non-unique identifiers

• File Organization - way data is stored



• File Access - way the computer locates stored records



• Sequential file processing - process master and transactions in same order

1. Read master record
2. Read transaction and match to master record by key
3. Update master record
4. Read next transaction
5. Compare key to master and update if a match
6. If no match, write master record to new master file
7. If key of transaction is smaller, master record may have been lost necessitating writing to an error file
8. New transaction is read
9. Next master is updated - continue

• Direct-access file processing - transactions processed as they occur, master and transactions can be in an order (good when files constantly updated)

1. Users sign on system
2. System prompts for transaction input
3. System searches for matching master record
4. In no match, error message is sent to correct error input
5. If match, master is updated
6. Updated record is written back to storage
7. System prompts for more input

• Indexed file organization

1. Primary keys and address locations of data stored in index file
2. Users key in primary key and location is found in index

• Indexed sequential-access method (ISAM)

1. Records stored sequentially, then indexed for access.
2. Requires more storage space for indexes
3. File needs to be reorganized periodically for adds and deletes

• Multi-attribute search file organization - access through secondary keys

1. Linked list - pointer field to next record in file, forming chains
2. Inverted list - pointers stored in an index

• Batch processing - processing similar transactions in groups

1. Remote batch - transactions recorded in machine readable form at dispersed locations

• On-line processing

1. Batch - data are captured for later processing
2. Real-time - data captured, edited, immediately processed, output displayed

Information Output

• Documents - records of transactions or other data, hardcopy - paper or softcopy-screen output



• Reports - internal and external users

1. Regular, scheduled
2. Exception basis

• Queries - user requests for information



• Goals of information

1. External users - stewardship requirements - tax, SEC
2. Internal users - planning and control

Top of document

Back to AIS Daily Schedule

Back to AIS Home Page

Back to Burke Home Page