Module 41: Information Technology Flashcards
information system within a business
an information system processes data and transactions to provide users with the information they need to plan, control and operate an organization, including:
- collecting transaction and other data
- entering it into the information system
- processing the data
- providing users with the information needed
- controlling the process
advantage of computer systems versus manual systems
computer processing tends to reduce or eliminate processing time, and prevent computational errors and errors in processing routine transactions (when fraud is not involved)
General types of IT systems
- office automation systems
- transaction processing systems
- management reporting systems
- management information systems
Management reporting systems
designed to help with the decision making process by providing access to computer data types: 1. management information systems 2. decision support systems 3. expert systems 4. executive information systems
office automation systems
designed to improve productivity by supporting daily work of employees (e.g. word processing, spreadsheets, presentation tools, email, electronic calendars, contact management software
transaction processing systems
involve the daily processing of transactions (e.g. airplane reservations systems, payroll recording, cash receipts, cash disbursements)
management information systems
(management reporting system) systems designed to provide past, present and future information for planning, organizing and controlling the operations of the organization
decision support systems
(management reporting system) computer based information systems that combine models and data to resolve non-structured problems with extensive user involvement
expert support systems
(management reporting system) computer systems that apply reasoning models to data in a specific relatively structured area to render advice or recommendations, much like a human expert
executive information systems
(management reporting system) computerized systems that are specifically designed to support executive work
the two distinct roles for systems
- recording of transactions of various types
2. providing support for decision making
designing and implementing a new information and control system provides an opportunity to reexamine
business processes, especially if the new system is an enterprise resource planning (ERP) system; more efficient and effective
Systems development lifecycle (SDLC)
the traditional methodology for developing information systems
characterized by its phases, each representing a specific set of development activities:
- planning
- analysis
- design
- development
- testing
- implementation
- maintenance
SDLC Planning Phase
- identify the problems that proposed system will solve
- define the system to be developed (based on strategic goals of the organization)
- determine the project scope (what the system will do and how it will be evaluated); a project scope document is used and can be revisited and revised
- develop a project plan- defines the activities that will be performed, and the individuals and resources that will be used; a project manager develops the plan and tracks its progress; sets project milestones
- evaluate the initial feasibility of the project- can involve determining the project’s technical, organizational, and economical feasibility
SDLC Analysis Phase
Involves teams including end users, information technology specialists, systems analysts, and process design specialists to understand the requirements for the proposed system
- Typically, processing data, and logic models are produced to help determine system requirements; a needs assessment may also be performed
- Next, an analysis is performed on the existing system along the same dimensions
- then a gap analysis is performed to examine the differences (gaps) between the required system and the existing system
- Finally, priorities are established for the gaps, which will be documented in a requirements definition document, which will receive sign-off from the end users
* It is during this phase that a company can take advantage of processes inherent in the new system to improve the existing process
A needs assessment (SDLC analysis phase)
involves determining the requirements for the system in terms of processes, data capture, information and reporting
Requirements definition document (SDLC analysis phase)
final document that outlines the differences between the required system and the existing system (requirements) that will receive a sign-off from end users
Specific specification documents contain information on basic requirements which include (SDLC analysis phase)
- performance levels
- reliability
- quality
- interfaces
- security and privacy
- constraints and limitations
- functional capabilities
- data structures and elements
The Design Phase (SDLC)
the primary goal of the design phase is to build a technical blueprint of how the proposed system will work
the components that are typically designed during this phase include:
- databases
- user interfaces for input and output
- required reports
- programs
- infrastructure and controls
The Development Phase (SDLC)
documents from the design phase are transformed into the actual system
the platform on which the system is to operate is built or purchased off-the-shelf and customized and databases are developed
The Testing Phase (SDLC)
involves verifying that the system works and meets the business requirements as set forth in the analysis phase
tests that should be performed:
- unit testing
- system testing
- integration testing
- user acceptance testing
unit testing (testing phase test)
involves testing the units or pieces of code
system testing (testing phase test)
involves testing the integration of the units or pieces of code into a system
integration testing (testing phase test)
involves testing whether the separate systems can work together
user acceptance testing (testing phase test)
determines whether the system meets the business requirements and enables users to perform their jobs efficiently and effectively
The Implementation Phase (SDLC)
involves putting the system in operation by the users; in order to effectively implement the system, detailed user documentation must be provided to the suers and the users must be adequately trained
implementation methods include:
- parallel implementation
- plunge implementation
- pilot implementation
- phased implementation
parallel implementation (implementation phase)
uses both systems until it is determined that the new system is operating properly
this has the advantages of a full operational test of the new system with less risk of system disaster
the disadvantage is the additional work and cost during the period both systems are operating
plunge implementation (implementation phase)
the organization ceases using the old system and begins using the new system immediately
less costly than the parallel method but it has a higher risk of system breakdown
pilot implementation (implementation phase)
involves having a small group of individuals using the new system until it is seen to be working properly
has the advantage of providing a partial operational test of the new system at a lower cost than parallel implementation
phased implementation (implementation phase)
involves installing the system in a series of phases (e.g. GL, AR, etc)
The Maintenance Phase (SDLC)
involves monitoring and supporting the new system
in this phase the organization provides ongoing training, help desk resources, and a system for making authorized and tested changes to the system
Types of Computers
- supercomputers
- mainframe computers
- servers
- microcomputers
- tablets/ smart phones/ personal digital assistants
supercomputers
extremely powerful, high speed computers used for extremely high-volume and/or complex processing needs
mainframe computers
large, powerful, high-speed computers; less powerful than super computers but they have traditionally been used for high-volume transaction processing
clusters of low cost, less powerful “servers” are increasingly taking over the processing chores of mainframe computers
servers
high-powered microcomputers that “serve” applications and data to clients that are connected via a network (web servers/ database servers)
typically have greater capacity (faster processors,more RAM, more storage capabilities) than their clients (microcomputers) and often act as a central repository for organizational data
servers today are often configured as a “virtual machine,” meaning multiple operating systems can coexist and operate simultaneously on the same machine
virtual machines are appealing because they lower hardware costs and create energy savings
Microcomputers
e.g. desktop computers, laptop computers
designed to be used by one person at a time (personal computers)
typically used for word processing, email, spreadsheets, surfing the web, creating and editing graphics, playing music, and gaming
tablets/ smart phones/ personal digital assistants
e.g. iPad, iPhone, android, blackberry
these are typically smaller, handheld wireless devices that depend on WiFi and/ or cellular technology for communications
Central Processing Unit (CPU)
the principal hardware components of a computer
contains:
- arithmetic/ logical unit
- primary memory
- control unit
major function is to fetch stored instructions and data, decode the instructions, and carry out the instructions
Arithmetic/ logical unit (CPU)
performs mathematical operations and logical comparisons
Primary memory (CPU storage)
active data and program steps that are being processed by the CPU
it may be divided into RAM (random-access memory) and ROM (read-only memory)
application programs and data are stored in the RAM at execution time
Control Unit (CPU)
interprets program instructions and coordinates input, output, and storage devices
random (RAM)
=direct storage
Secondary Storage Devices
- magnetic tape
- magnetic discs
- RAID (Redundant array of independent [previously, inexpensive] disks)
- compact discs
- solid state drives (SSDs)
- could-based storage
magnetic tape
slowest type of storage available because data is stored sequentially
primarily used for archiving purposes today
magnetic disks
the most common storage medium in use on computers today
also called “hard disks” or “hard disk drives: (HDD)
data can be accessed directly
RAID (Redundant array of independent [previously, inexpensive] disks)
a way of storing the same data redundantly on multiple magnetic discs (back-up)
- when originally recorded, data is written to multiple discs to decrease the likelihood of loss
- if a disk fails, at least one of the other disks has the information and continues operation
compact discs
discs (CDs) and digital video discs (DVDs)
both are the same physical size and both use optical technology to read and write data to the disc
solid state drives (SSDs)
use microchips to store data and require not moving parts for read/write operations
SSDs are faster and more expensive per gigabyte than CDs, DVDs, and HDDs
SSDs are increasingly being used in place HDDs in microcomputers but cost and limited capacity have constrained their adoption as a primary storage device
more commonly used for auxiliary storage
SSDs that are “pluggable” are often called “thumb drives” “flash drives” or “USBs”
cloud based storage
also called “storage as a Service” (SaaS)
hosted offsite, typically by third parties, and is accessed via the internet
manner in which information is represented in a computer
- digital
2. analog
digital (manner in which information is represented in a computer)
a series of binary digits (0s and 1s)
one binary is called a “bit”
a series of 8 bits is referred to as a “byte”
one byte can form a letter, a number, or special character (e.g. 00000111 is the binary equivalent of the decimal number 7)
analog (manner in which information is represented in a computer)
the representation that is produced by the fluctuations of a continuous signal (e.g. speech, temperature, weight, speed, etc.)
rather than using 0s and 1s to represent information analog signals use electrical, mechanical, hydraulic or pneumatic devises to transmit the fluctuations in the signal itself to represent information
Online
equipment in direct communication with, and under the control of, the CPU
online also refers to having a connection to the Internet
Off-Line
equipment not in direct communication with the CPU; the operator generally must intervene to connect off-line equipment or data to the CPU (e.g. mount a magnetic tape of archival data)
Off-line also refers to the absence of an Internet connection
Console
a terminal used for communications between the operator and the computer (e.g. the operator of a mainframe computer)
peripheral equipment
all non-CPU hardware that may be placed under the control of the central processor
classified as online or off-line, this equipment consists of input, storage, output, and communications
controllers
hardware units designed to operate specific input-output untits
buffer
a temporary storage unit used to hold data during computer operations
MIPS
millions of instructions per second; a unit for measuring the execution speed of computers
Input Devices
- keying data- data entry devices
- online entry
- turnaround documents
- automated source data input devices
- electronic commerce and electronic data interchange
Key-to-Tape and Key-to-disk (keying data- input device)
data is entered on magnetic tape and/ or disk respectively and then read into a computer
visual display terminal/monitor (online entry)
uses keyboard to directly enter data into computer
1. input interface- a program that controls the display for the user (usually on a computer monitor) and that allows the user to interact with the system
- graphical user interface (GUI)- uses icons, pictures, and menus instead of text for inputs (e.g windows)
- command line interface- uses text-type commands (e.g barcodes)
mouse, joystick, lightpens (online entry)
familiar devices that allow data entry
touch-sensitive screen (online entry)
allows users to enter data from a menu of items by touching the surface monitor
turnaround documents (input devices)
documents that are sent to the customer and returned as inputs (e.g. utility bills; to make payments “remittance”)
automated source date inputs devices
- magnetic tape reader
- magnetic ink character reader (MICR)
- scanner
- automatic teller machine (ATM)
- radio frequency identification (RFID)
- point of scale (POS) recorders
- voice recognition
magnetic tape reader (automated source date inputs devices)
a device capable of sensing information recorded as magnetic spots on magnetic tape
magnetic ink character reader- MICR (automated source date inputs devices)
device that reads characters that have been encoded with a magnetic ink (e.g. bank check readers)
Scanner (automated source date inputs devices)
a device that reads characters on printed pages
Automatic teller machine- ATM (automated source date inputs devices)
a machine used to execute and record transactions with financial institutions
Radio Frequency Identification- RFID (automated source date inputs devices)
uses radio waves to track and input data (e.g. wave card entry)
increasingly used for inventory and contactless payment systems
RFID tags can be read wirelessly by RFID readers; does not require line-of-sight access like bar code technology (e.g Mobil’s Speedpass payment systems, FasTrak toll collection system)
Point-of-scale recorders- POS (automated source date inputs devices)
devises that read price and product code data (purchasing groceries)
ordinarily function as both a terminal and a cash register
allows one to record and track customer orders, process credit and debit cards, connect to other systems in a network, and manage inventory
example: a POS system for restaurants is likely to have all menu items stored in a database that can be queried for information in a number of ways
Increasingly, POS terminals are also we-enabled, which makes remote training and operation possible, as well as inventory tracking across geographically dispersed locations
Voice recognition (automated source date inputs devices)
a system that understands spoken words and transmits them into a computer
Electronic commerce and electronic data interchange (input device)
involves one company’s computer communicating with another’s computer
example: a buyer electronically sending a purchase order to a supplier
Output devices
- many automated source data input devices and electronic commerce/electronic data interchange devices are capable of outputting data (writing in addition to reading) and therefore become output devices as well as input devices
- monitors
- printers
- plotters- produce paper outputs of graphs
- computer output to microfilm or microfiche (COM)- makes use of photographic process to store output
Systems software
- Operating system
- Utility programs
- Communications software
Operating system (systems software)
manages the input, output, processing and storage devices and operations of a computer (Windows, Linux, Unix)
Performs scheduling, resource allocation, and data retrieval based on instructions provided in job control language
Utility programs (systems software)
handle common file, data manipulation and “housekeeping” tasks
Communications software (systems software)
controls and supports transmission between computers, computers and monitors, and access various databases
Software- computer programs that control hardware
- systems software
2. applications software
Applications software
programs designed for specific uses, or “applications”, such as
- word processing, graphics, spreadsheets, email, and database systems
- accounting software
Accounting software (applications software)
- low-end: all in one package, designed for small organizations (quickbooks, peachtree, dell-tech)
- high-end: ordinarily in modules (e.g. general ledger, receivables)
- Enterprise resource planning (ERP): designed as relatively complete information system “suites” for large and medium size organizations (e.g. human resources, financial applications, manufacturing, distribution). Major vendors are well known- SAP, People Soft, Oracle, and J.D. Edwards
ERP System Advantages
Integration of various portions of the information system, direct electronic communication with suppliers and customers, increased responsiveness to information requests for decision-making
i.e. its all done for you; you have good support
ERP System Disadvantages
Complexity, costs, integration with supplier and customer systems may be more difficult than anticipated
**very expensive
Complier (software term)
produces a machine language object program from a source program language
Multiprocessing (software term)
simultaneous execution of two or more tasks, usually by two or more CPUs that are part of the same system
Multitasking (software term)
the simultaneous processing of several jobs on a computer
Object program (software term)
the converted source program that was changed using a compiler to create a set of machine readable instructions that the CPU understands
Source program (software term)
a program written in a language from which statements are translated into machine language; computer programming has developed in “generations”
Source Programming “Generations”
- machine language
- assembly language
- “high-level” programming languages such as COBOL, Basic, Fortran, C++, and Java
- an “application- specific” language usually built around database systems (i.e. SQL, a structured query language)
- a relatively new and developing form that includes visual or graphical interfaces used to create source language that is usually compiled with a 3rd or 4th generation language compiler
Machine language (source programming generation 1)
composed of combinations of 1’s and 0’s that are meaningful to the computer (binary)
“high-level” programming languages such as COBOL, Basic, Fortran, C++, and Java (source programming generation 3)
C++ and Java are considered object-oriented programs (OOP) in that they are based on the concept of an “object” which is a data structure that uses a set of routines, called “methods,” which operate on the data
The “objects” are efficient in that they often are reusable in other programs
Object-oriented programs keep together data structures and procedures (methods) through a procedure referred to as encapsulation.
assembly language (source programming generation 2)
a low-level programming language that uses words (mnemonics) instead of numbers to perform an operation.
assembly language must be translated to machine language by a utility program called an “assembler”
generally, an assembly language is specific to a computer architecture and is therefore not portable like most high-level languages
virtual memory (software term)
(storage) online secondary memory that is used as an extension of primary memory, thus giving the appearance of larger, virtually unlimited internal memory
protocol (software term)
rules determining the required format and methods for transmission of data
desk checking (programming term)
review of a program by the programmer for errors before the program is run and debugged on the computer
debug (programming term)
to find and eliminate errors in a computer program
many compliers assist debugging by listing errors in the program such as invalid commands
edit (programming term)
to correct input data prior to processing
loop (programming term)
a set of program instructions performed repetitively a predetermined number of times, or until all of a particular type of data has been processed
memory dump (programming term)
a listing of the contents of storage
patch (programming term)
a section of coding inserted into a program to correct a mistake or to alter a routine
run (programming term)
a complete cycle of a program including input, processing and output
Methods of Processing
- batch or online real-time
2. centralized, decentralized, or distributed
batch processing
transactions flow through the system in groups of like transactions (batches).
Example: all cash receipts on accounts receivable for a day may be aggregated and run as a batch
ordinarily leaves a relatively easy-to-follow audit trail
*goes through edit checks and prints out errors (admin fee process)
online real-time processing (or direct access processing)
transactions are processed in the order in which they occur, regardless of type.
data files and programs are stored online so that updating can take place as the edited data flows to the application
system security must be in place to restrict access to programs and data to authorized persons
categorized into:
- online transaction processing (OLTP)
- online analytical processing (OLAP)
online transaction processing-OLTP (online real-time processing)
- databases support day-to-day operations
2. example: airline reservation systems, bank automatic teller systems, internet website sales systems
online analytical processing- OLAP (online real-time processing)
enables the user to query the system (retrieve data), and conduct an analysis, etc.; primarily used for analytics
uses statistical and graphical tools
example: airline company downloads its OLTP reservation info into another database to allow analysis of that reservation information
decision support systems
computer-based info systems that combine models and data in an attempt to solve relatively unstructured problems with extensive user involvement
one approach to OLAP (online analytical processing) is to periodically download and combine operational databases into a
- data warehouse: a subject-oriented, integrated collection of data used to support management decision-making processes or;
- a data mart: a data warehouse that is limited in scope
data mining
using sophisticated techniques from statistics, artificial intelligence and computer graphics to explain, confirm and explore relationships among data (which is often stored in a data warehouse or data mart)
*Business intelligence (BI)
a combination of systems that help aggregate, access, and analyze business data and assist in the business decision-making process
Artificial intelligence (AI)
computer software designed to help make decisions (may be viewed as an attempt to model aspects of human thought on computers)
Expert system
one form of AI (artificial intelligence)
a computerized information system that guides decision processes within a well-defined area and allows decisions comparable to those of an expert
example: an expert system may be used by a credit card company to authorize credit card purchases to minimize fraud and credit losses
Centralized Processing
processing occurs at one location
Decentralized Processing
processing (and data) are stored on computers at multiple locations
may be viewed as a collection of independent databases
Distributed Processing
transactions for a single database are processed at various sites
processing may be either a batch or online real-time basis
bit
a binary digit (0 or 1) which is the smallest storage unit in a computer
byte
a group of adjacent bits (usually 8) that is treated as a single unit, or character, by the computer.
one byte can form a letter, a number, or a special character, or unprintable codes (those that control peripheral devices such as computers)
Field
a group of related characters (social security number)
Record
an ordered set of logically related fields
example: all payroll data (including SS number field and others) relating to a single employee
File
a group of related records (e.g. all the weekly pay records YTD), which is usually arranged in sequence
Table
a group of related records in a relational database with a unique identifier (primary key field) in each record
database
a group of related files or a group of related tables (if a relational database)
ordinarily stored online
Master file
a file containing relatively permanent information used as a source of reference and periodically updated with a detail (transaction) file (e.g. permanent payroll files- all banking information)
detail or transaction file
a file containing current transaction information used to update the master file (e.g. hours worked by each employee during the current period used to update the payroll master file)
detail or transaction file
a file containing current transaction information used to update the master file (e.g. hours worked by each employee during the current period used to update the payroll master file)
traditional file processing systems
focus upon data processing needs of individual departments; each application program or system is set up to meet the needs of the particular requesting department or user group
advantages of traditional processing systems
- currently operational for many existing systems
2. cost effective for simple applications
disadvantages of traditional processing systems
- data files are dependent upon a particular application program
- in complex systems, there is much duplication of data
- each application must be developed individually
- program maintenance is expensive
- data may be difficult to share btwn functional areas (isolated)
normalization
the process of separating the database into logical tables to avoid certain kinds of updating difficulties (referred to as “anomalies”)
database system
computer hardware and software that enables the database to be implemented
database management system
software that provides a facility for communications btwn various applications programs (e.g. a payroll prep program) and the database (e.g. master payroll file containing earnings)
*create and modify
data independence
basic to database systems is this concept which separates the data from the related application program
data modeling
identifying and organizing a database’s data, both logically and physically.
data model determines what info is to be contained in a database, how the info will be used, and how the items in the database will be related to each other
entity-relationship modeling
an approach to data modeling
the model (called entity-relationship diagram, or ERD) divides the database into two logical parts:
- entities (e.g. customer, product) and
- relations (e.g. buys, pays for)
primary key
the fields that make a record in a relational database table unique
foreign key
the fields that are common to two (or more) related tables in relational database
REA data model
a data model designed for use in designing accounting information databases
Resources; Events; Agents
Data Dictionary
(data repository or data directory system)
data structure that stores meta-data
meta-data
definitional data that provides info about or documentation of other data managed within an application or environment
i.e. data about data elements, records and data structures (length, fields, columns)