Study Notes

Project Management Project Management is a planned and ongoing process that guides all the

development tasks and resources throughout a projects development A Project Plan organises the project by specifying who will do the task, what

has to be done, how the task is done, what resources are required, and what is to be expected

PROJECT MANAGEMENT TECHNIQUES Active Listening: Listening to people is the main source of critical

information required for a project to run smoothly. Listening is not the same as hearing; to listen requires attention and involvement

Mirroring: Involves repeating back some of the speakers key words – indicating that you are interested and would like to know and understand more

Paraphrasing: Listener uses their own words to explain what they think the speaker just said. The listener reflects feelings as well as meaning in their response

Summarising: Listener confirms their understanding in the speakers mind, and hence helps to bring the conversation to an end

Clarifying: Listener asks questions or makes statements that encourage the speaker to provide more detailed explanations

Motivational: Encourage the speaker and reinforce in their mind that you are indeed listening and are interested in what they have to say

Conflict Resolution: Need to manage conflict so that issues are resolved appropriately for all concerned, and in the best interests of the project

Negotiation Skills: Negotiation should be a friendly exchange where differences are argued logically and in a reasoned manner. This can even prevent situations leading towards conflicts

TEAM BUILDING SKILLS “Tuckman” Stages of Team Development: 1. Forming – Team members are only just getting to know each other 2. Storming – People are beginning to feel comfortable with each other 3. Norming – Team members now recognise their differences 4. Performing – The team is now operating as an effective, productive unit

Team Building – building a team of two or more people with complimentary skills, behaviours and personalities who are committed to achieving a common goal

Advantages – The people within the team are much more productive, and the systems they develop are of higher quality

Disadvantages – Financial loss, employment loss and missed opportunities – unable to meet deadlines, produce quality work and operate within financial constraints

PROJECT PLAN INCLUDES: Gantt Chart: Indicates when tasks need to be completed by

Journal and Diary Entries: The diary is a record of appointments, events and meetings. The journal is a detailed record of what happened at each meeting, how tasks have been allocated, and when tasks are to be completed

Funding Management Plan: Record of the scheduling and costing of tasks, and other expenses

Communication Management Plan: Record of when meetings are to be held throughout the development of the information system

SOCIAL AND ETHICAL ISSUES The work environment, including health and safety issues such as ergonomic

design of furniture, appropriate lightning, and appropriate noise levels Security of data and information during development Copyright issues including who will retrain the copyrights for the new system Respect for the rights of needs and individual team members – such as privacy

1) UNDERSTANDING THE PROBLEM Systems Analyst: A person who analyses systems, determines requirements

and designs new information systems Requirements: Features, properties or behaviours that a system must have to

achieve its purpose Key Question 1: What are the problems with the existing system? Key Question 2: How does the existing system work? An understanding of

the operations of the existing system must be understood Key Question 3: How do you identify the problems with the existing system? Answer to Question 3: Interview and Survey PARTICIPANTS in the existing

system – They are able to identify problems and often they also have ideas in regard to solving these problems

Answer to Question 3: Interview and Survey USERS in the existing system – Most information systems are primarily concerned with fulfilling the needs of its users, so their views and opinions on the systems are vital

Prototype: Needs to be developed, and is produced to clarify how the system works, as well as clarify the nature of the problem, and represent how the new system may work

After all the information has been gathered, a REQUIREMENTS REPORT is produced – A statement about the purpose/requirements of the new information system

A requirements report includes aims and objectives of the system, and how it will HELP the organisation

2) MAKING DECISIONS/PLANNING Economic: to determine whether the system is affordable . This involves

cost/benefit analysis to determine both initial costs to implement the system, and then recurring costs to maintain the system

Operational: to determine whether a system will be usable by the target customers. The users must be able to effectively use, or to operate, the system

Technical: to determine what hardware and software (Information Technology) is currently being used, and then to determine whether the hardware and software to build the system exists

Scheduling: to determine the time frame in which a system must be developed. To determine whether it will be able to be completed within the

specified time frame, it is useful to use project planning tools, such as Gantt Charts

Traditional (Structured): AS the name suggests, involves very structured, step-by-step stages, which each must be completed before proceeding to the next step. – 1. Understanding the problem, 2. Planning, 3. Designing, 4. Implementing, 5. Testing, Evaluating and Maintaining

Outsourcing: Involves using another company to develop parts of the system, or even the complete system

Prototyping: A CIRCULAR approach to systems development, and new prototypes of the system are constantly being made in a loop before implementation: Designing > Testing/Evaluating > Understanding the Problem > Designing…. The prototypes eventually evolve to a point where they become the final solution, and are essentially ready to move out of the loop, and for the next stage - implementation

Customisation: An existing system is customised to suit the needs and requirements of the new system. In reality – most business systems are customised versions of existing systems

Participant: Means that the same people who will use and operate the final system develop the system

Agile: An approach that places emphasis on the team developing the system rather than following a predefined structured development process

3) DESIGNING SOLUTIONS/DESIGNING Design Tools: System Flowcharts are a diagrammatic way or representing both the flow of

data and logic through an information system

Data Flow Diagrams describe the path data takes through a system. No logic, and no attempt is made to indicate the timing of events

Context Diagrams are used to represent entire information systems

A Data Dictionary contains a comprehensive description of each field in one of the databases associated with the information system. It commonly includes (4): field name, data type, field size, and a description of the purpose

Storyboards give a general overview of the information system. They are used to document the screens used in a system, and the flow between them.

Storyboards emphasise the user interface of a system rather than the functions performed by the system

Linear Storyboard: modules are arranged in a sequence

Hierarchical Storyboard: modules are arranged in descending levels

Decision Tables represent all possible conditions and actions that will resultCONDITIONS RULES - - -Mark >= 80 Y N N N

Mark >= 60 and <80

N Y N N

Mark >=45 and <60

N N Y N

Mark <45 N N N YOUTCOMES GRADES - - -A XB XC XD X

Decision Trees are a diagrammatic representation of all possible combinations of decisions, and their resulting actions

The new system can be developed from a PROTOTYPE Screen Designs for input and output of data must be created The Technical specifications of hardware must be identified before hardware

is bought and installed Purchasing application software that is readily available may satisfy the

software requirements of the new system IF however this does NOT meet exact requirements, then custom software

will need to be written by programmers

The new system MUST be tested before implementation! Test Data is prepared to test any potential problem Documentation of the new system is required, which includes a written

description of the development and operation of the information system User Documentation provides direction for any person using the system, and

is also necessary to include. It can be in the form of on-screen help, or a user manual

4) IMPLEMENTATION/IMPLEMENTING

Direct: This method involves the old system being completely dropped and the new system being completely implemented at the same time

Parallel: This method involves operating both systems for a period of time, which allows for any major problems faced with the new system to be encountered and corrected without a loss of data

Phased: This method involves the gradual introduction of the new system whilst the old system is progressively discarded

Pilot: This method involves the new system being installed for a small number of users. These users learn, use and evaluate the new system. Once the new system is deemed to be performing satisfactorily then the system is installed for use by everyone

Training Techniques Traditional Group Training Sessions: The training is performed by a trainer

to a group of people onsite, or at separate premises. The trainer can be a member of the system development team, or an outsourced specialist

Peer Training: One or more users undergo intensive training in regard to the operation and skills needed by the system

Online Training: Online tutorials and help systems allow users to learn new skills at their own pace, and as they are needed

Operation Manuals: Printed operation manuals contain procedural information which describes step-by-step instructions specific to the new system

5) TESTING, EVALUATING AND MAINTAINING Testing Acceptance Tests: Formal tests conducted to verify whether or not a system

meets its requirements: 1) Volume data: Ensures the system performs within its requirements when

processes are subjected to large volumes of data

2) Simulated data: Tests the performance of systems under simulated operational conditions, allowing an evaluation of the systems performance to be completed under a variety of scenarios

3) Live data: Takes place once a system has been installed to ensure that the system is operating as expected, and that it operates under real conditions

Evaluation/Evaluating Evaluation is the process of examining a system to determine the extent to

which it meets its requirements Evaluation is ONGOING IF the new system is not performing, chances will need to be made, AND the

SDLC will start again! Technical Performance Monitoring aims to evaluate the continuing

achievement of the systems evolving requirements – some old requirements may go down in priority over time, or even become irrelevant

Financial Performance Monitoring is largely about evaluating the accuracy of the real economic situation against the economic predictions made in the feasibility study

Maintenance/Maintaining Maintenance is any modification to the system by making minor

improvements Maintenance may involve installation of new hardware and software Involves: 1. Regular Maintenance, 2. Repairs when faults occur For each modification, the SDLC commences AGAIN! This occurs because it is necessary to ensure the modification works correctly

with all parts of the existing system, and also to ensure all documentation is updated (Any changes MUST be documented!)

Examples of Maintenance: Perform regular backups of the systems data, and ensure these backups are

secured in a safe location Maintain hardware by carrying out all recommended cleaning, as well as other

maintenance tasks Protect against viruses by ensuring virus protection software is used and

updated

An OPERATIONS Manual is created to detail the procedures which the PARTICIPANTS must follow in using the new system

The Operations Manual should (3): 1) Be in a user-friendly format 2) Have clear and concise instructions 3) Contain Screen Dumps

Communication Systems

Communication systems enable people and systems to share and exchange data and information electronically

CHARACTERISTICS OF COMMUNICATION SYSTEMS IPT Presentation Level – 7) Application Layer, 6) Presentation Layer IPT Communication and Control Level – 5) Session Layer, 4) Transport

Layer, 3) Network Layer IPT Transmission Level – 2) Data Link Layer, 1) Physical Layer

MAC Address: A hardware address that uniquely identifies each node on a network

The message is created at the source using some type of software application When a message is prepared for transmission, it descends the stack of

protocols from the Application Level, down to where it is ready for physical transmission by the hardware operating at the IPT transmission level

The main task of the transmitter is to represent individual bits as a wave – this wave is the signal that is actually transmitted through the medium

Transmission occurs as a signal travels through the medium To accurately decode a signal requires the receiver to sample the incoming

signal using precisely the same timing used by the transmitter during encoding During transmission data packets may pass through many different links, and

it is likely that packets forming part of a single file will travel over quite different paths from the transmitter to the receiver

As messages descend the stack prior to transmission, many protocols calculate checksums or CRC values for error detection and correction, and include them within their header or footers

Many protocols restrict messages based on user names and passwords, and others go a step further by encrypting messages during transmission

Protocol: A formal set of rules and procedures that must be observed for two devices to transfer data efficiently and successfully

Handshaking: The process of negotiating and establishing the rules of communication between two or more devices

HTTP: Operates within the PRESENTATION LAYER (layer 6), and is the primary protocol used by web browsers to communicate and retrieve web pages from web servers

TCP: Operates within the TRANSPORT LAYER (layer 4), and together with IP, it is responsible for the transmission of most data across the internet. Its PRIMARY RESPONSIBILITY is to ensure messages are delivered correctly

IP: Operates within the NETWORK LAYER (layer 3), and is the protocol that causes data packets to move from sender and receiver

Each device on the internet must have at least one unique IP address, for example: 140.123.54.67

Ethernet: Operates at DATA LINK LAYER (layer 2) and the PHYSICAL LAYER (layer 1), and because it operates at a physical level, it must be built into the various hardware devices used to transmit and receive

Bits Per Second: The number of bits transferred each second – the speed of BINARY data transmission

Baud Rate: The number of signal events occurring each second along a communication channel

Bandwidth: The difference between the highest and lowest frequencies in a transmission channel, expressed in Hertz (Hz)

Parity bit check: Seven bits represent the normal ASCII character set when an eight-bit byte is used in a computer. The eighth bit can be used to check whether that byte has been received correctly by counting the number of 1’s – making it odd or even.

Example of ^: If the number of 1’s is three, which is odd, we add 0 as the parity bit to maintain odd parity checking: 01010010

Checksums: All the 1s and 0s in a block of data are summed to make a total and the receiver calculates a checksum value. If the sent value does not agree, then an error is detected. The position of the error is unknown

Cyclical Redundancy Check (CRC): The checksum number is substituted into a formula, and a 16-bit remainder is calculated. Once it has reached its destination, the received checksum is put through the same process. If the remainder produced is identical to the one received, then it has been correctly received

EXAMPLES OF COMMUNICATION SYSTEMS Internet: The internet is a worldwide packet switched public network based

on the internet protocol Public Switched Telephone Network (PSTN): is the network of the world's

public circuit switched telephone networks An Intranet is a private network maintained by a company or government

organization, and is based on the Internet Protocol Extranets are an extension of an intranet to allow access to customers and

other users outside the organization Teleconferencing is the live exchange of information among several people

and machines remote from one another, but linked by a single telecommunications system

A rotary dial telephone is activated by rotating the numeric dial instead of activating push buttons. Its an old fashioned and traditional telephone

A fax is a telecommunications technology used to transfer copies of documents using affordable devices operating over the telephone network

Voice mail is a computerised method of storing and forwarding spoken messages

Voice Over Internet Protocol (VoIP) refers to communications services that are transported via the Internet rather than the public switched telephone network(PSTN)

E-mail is a method of exchanging digital messages. E-mail systems are based on a store-and-forward model in which e-mail computer server systems accept, forward, deliver and store messages on behalf of users

E-mail uses two different APPLICATION level protocols – SMTP, and either POP or IMP

Multipurpose Internet Mail Extensions (MIME): The protocol used to code non-textual data and attachments into ASCII so that it can be transmitted within e-mail messages

Simple Mail Transfer Protocol (SMTP): The protocol used to send e-mails from an e-mail client, to an SMTP server, and also to transfer e-mail between SMTP servers

Automatic Teller Machines (ATM): is a computerised telecommunications device that provides the clients of a financial institution with access to financial transactions in a public space without the need for a cashier or a bank teller

Electronic Funds Transfer at Point of Sale (EFTPOS) works through the customer’s card details being swiped in a magnetic strip reader, and this then allows the direct transfer of the necessary funds from the customers account into the retailers account

Internet Banking: allows customers to pay bills, transfer money between accounts and perform various other functions from the comfort of their home or office

Trading over the Internet has become very popular as individuals and small businesses are able to sell items worldwide with little initial startup costs. Trading over the internet has created systems such as eBay and PayPal

Virtual Organisation: an organisation whose members are geographically separated

NETWORK COMMUNICATION CONCEPTS Client-server architecture: servers provide specific processing services for

clients. Clients request the service, and wait for a response while the server processes their request

Authentication: the process of determining is someone is who they claim to be

Physical Topology: the physical layout of devices on a network, and how the cables and wires connect these devices

Logical Topology: show how data is transmitted and received between devices REGARDLESS of their physical connections

Bus Topology: One of the simplest designs in networking, where a common cable (known as the “bus”) connects all the nodes in a bus topology. All nodes on the network receive data transmitted on a bus network, but only the node to which it is ADDRESSED accepts and processes the data

+ Easy to expand the network and add new nodes - If one node fails, the rest of the network will fail

Star Topology: All nodes connect to a central node via their own dedicated cable. Today the star topology is used on almost all LAN’s

+ Each node has its own cable, and can easily be removed without affecting any other nodes

- Lots of cabling, if the central node fails – the whole system fails

Ring Topology: Each node connects to exactly two other nodes. Data packets circulate the ring in just one direction - meaning each node receives the data from one node, and then transmits the data to another node. It is the least commonly used topology in LAN’s today

+ Least data collisions as data packets circulate the ring in one direction - If one node fails, then the entire ring is broken, and data stops

transferring

Mesh Topology: Include more than one physical path between the pair of nodes. This is the primary topology of the internet, where IP data packets can travel different paths from the transmitter to the receiver

Hybrid Topology: Hybrid topologies use a combination of connected bus, star and ring topologies. Hybrid topologies are the primary topology of most organisations networks

Converting analog data to digital data is done using an “analog to digital converter (ADC)”, and converting digital data to analog data is done using a “digital to analog converter (DAC)

NETWORK HARDWARE Twisted Pair: Consists of a pair of shielded copper wires twisted together.

Electrical interference is minimised, and makes it less vulnerable to signal

loss. Suited for very high bit rates over short distances, and lower bit rates over longer distances

Coaxial Cable: Was designed to transmit analog broadcast TV from antennas on Television sets, support high frequencies, and provide extra protection from electromagnetic interference. There are two types:

1) “Thinnet” – Max Distance 185M 2) “Thicknet” – Max Distance 500M Optic Fibre Cable: Able to support far higher data transfer rates over much

greater distances than either twisted pair OR coaxial cable. Completely immune to outside electrical interference, and the majority of major communication links connecting major cities and continents use optical fibre

Optic Fibre Cables consist of a light-transmitting glass core surrounded by a reflective cladding layer

Wireless Transmission Media: Use the atmosphere as the medium to carry electromagnetic waves between nodes

E.g. 1 – Terrestrial Microwave – Used to relay wireless signals over large distances

E.g. 2 – Satellite – Use microwaves to carry digital signals from and to both ground based stations, and also between satellites

E.g. 3 – Wireless LAN’s – Communicate using microwaves with frequencies in the vicinity of 2.4 GHz

E.g. 4 – Bluetooth – Communication system for short-range transmission, and operates within the vicinity of 2.4 GHz. It was designed to replace cables that connect portable devices

E.g. 5 – Infrared – Used over short distances, these infrared waves occur with frequencies of above microwaves and below invisible light in communication systems

E.g. 6 – Mobile Phones – Automatically adjust the power of their transmitters based on the signal level received from their current base station - reducing electromagnetic radiation, and extending battery life

Network Interface Card (NIC): converts data in between the computer into a form suitable for transmission across the network

Repeater: Any device that receives a signal, amplifies it and then transmits the amplified signal down another link – increasing the physical range of transmission media

HUB: Amplifies the packet of data, and it simply amplifies and retransmits the packet to all attached nodes

Bridge: Separates a network into different segments at the data link layer

Switch: An intelligent device for connecting nodes on a LAN. The message is directed to the intended receiver

Gateway: Connects two networks together Wireless Access Points: The central nodes on wireless LAN’s, and these

central nodes broadcast to all wireless nodes within the coverage area Modulation: The process of encoding digital information onto an analog

wave Demodulation: The process of decoding modulated analog wave back into its

original digital signal ADSL Modems: Use existing copper telephone lines to transfer broadband

signals Cable Modems: Connect to the internet via coaxial cables; usually the same

cable that transmits cable TV stations

Servers: Provide specific processing services to other nodes (clients) Fault Tolerance: The ability of a system to continue operating despite the

failure of one or more of its components File Servers: Manages storage and retrieval of files, and also application

software in response to client requests Print Servers: Controls access to one or more printers for many clients Database Servers: A database server executes SQL statements on behalf of

the client applications, and database management system software (DBMS) provides the connection to the database, and ensures the rules defined for the database are maintained

Mail Servers: Use two different protocols – SMTP, and either POP or IMAP, and these protocols run on servers associated with these protocols. E-mail clients, such as Microsoft Outlook, must communicate using these protocols

Web Servers: Essentially a web server provides services to web browsers – they retrieve web pages and transmit them back to the requesting client web browser

Proxy Servers: Sits between the clients and real servers, and tries to perform the request itself without bothering the real server

NETWORK SOFTWARE

Network Operating Systems (NOS): Installed on one or more servers where it provides various services to secure and support the networks resources and users – one vital service being the authentication of users based on their usernames and passwords

Network Administrators: The personnel responsible for the ongoing maintenance of network hardware and software

Task 1 – Adding and Removing Users: Each new user has an individual account created that includes their username and password, together with the details of any assigned policies and privileges

Task 2 – Assigning Printers: It makes sense to assign printers to workstations rather than users, as users will have access to a printer that is physically close to the workstations where they are currently logged on

Task 3 – Assigning file access rights: Also known as PERMISSIONS. File access rights determine the processes a user can perform on a file or directory at the file level:

Directory (Folder) Permissions (6): Full Control, Modify, Read and Execute, List Folder Contents, Read, Write

File Permissions (5): Full Control, Modify, Read and Execute, Read, Write Task 4 – Installation of software and sharing with users: It is the network

administrator who must ensure that software applications are installed on individual client workstations - making them available for use by any user that logs onto the workstation. NOS’ are able to automate this process – saving considerable time for network administrators

Task 5 – Client installation and protocol assignment: Every network will have a different specific set of steps for installing new clients, and it is commonly the network administrator who performs these installation steps. For example: 1) Ensuring the new machine has a compatible NIC installed, and 2) Ensuring the clients operating system is compatible with the NOS etc.

ISSUES

Internet Fraud: Some kind of deception that includes false statements that intentionally aim to cause another person to suffer a loss (e.g. Spam, Phishing and Identity Theft)

Power and Control: Those who control access to information are placed in a position of power over the users whose access they control. Not only can access be restricted, but the activities of users can also be MONITORED (e.g. Internet Filtering, Employers can watch internet sessions of employees etc.)

Removal of Physical Boundaries: In cyberspace, one’s physical location is of little or no relevance, and individuals and organisations can trade across the globe (e.g. Virtual organisations and communities are created as needs arise)

Interpersonal Issues: Electronic communication systems have changed the way many people have formed relationships. Ideas delivered electronically can often appear less forceful and caring when compared to face-to-face communication (e.g. Online Dating Sites)

Work and Employment Issues: Electronic communication systems have changed the way many people work and where they complete their work. They have provided the means for many people to work from home, or virtually any other location. Most research shows that people who work from home are more productive, and work longer hours. However, working from home can also present problems as people must find the balance between work and their personal lives

Multimedia Systems Multimedia systems combine different types of media into interactive

information systems

DIFFERENCES BETWEEN MULTIMEDIA AND PRINT Mode of Display – Print media is hard copy, Multimedia can be implemented

for computer use Interactivity – The user is able to make an immediate response to what is

happening in multimedia Dynamic Nature – Once a book is published, it cannot change. A multimedia

product can change either by the user (preferences), or the author (edit, new versions)

Ease of Distribution – Multimedia is easy to distribute between other computers, making it very convenient. Printing requires scanning the document onto the computer using a scanner

CHARACTERISTICS OF EACH OF THE MEDIA TYPES Text and Numbers: Two most common methods of digitally representing

texts are ASCII and EBCDIC In multimedia systems, both texts and numbers are displayed as IMAGES

using FONTS Raster Fonts: store a bitmap of each character Outline Fonts: describe characters using mathematical descriptions

Hyperlinks: The organisation of hypertext and hypermedia is based on hyperlinks. In everyday usage, the word hypertext has taken the same meaning as hypermedia!

Hypertext: Bodies of text that are linked in a non-sequential manner

Hypermedia: Extension of hypertext to include links to a variety of different media types, e.g. Sound and Images

Within Multimedia systems, hyperlinks are routinely constructed to transfer the user to other parts of the PRESENTATION

Audio: All waves have two essential components – frequency and amplitude Frequency: measured in HERTZ (Hz) and is the number of times per second

that a COMPLETE WAVELENGTH occurs Amplitude: measured in DECIBELS (db) and determines the volume or

level of sound. Very low amplitude waves cannot be heard, whereas very high levels can damage hearing

Sampled Audio: The level of an audio signal recorded at precise intervals Individual Notes: Represented digitally as a series of individual notes

Images: Two different techniques for representing images – BITMAP and VECTOR

Bitmap: Represent each element or dot in the picture separately. Each dot (pixel) can be a different colour – represented by a binary number

8 Bits are required for EACH PIXEL (1 byte = 8 bits) Vector: Represent each portion of the image mathematically, just like

OUTLINE FONTS Each shape within the vector image is a separate object, and can be altered

without affecting other objects

Animation: Displaying a sequence of images one after another Cel-based animation: A sequence of images (cel) with small changes

between each cel – an illusion of movement is created Path-based animation: A line (path) is drawn for each character to follow –

the character moves along the line when the animation is playing Animated Gifs = Cel-Based and Flash .SWF Format = Both (Animation is

organised as VECTOR images) Morphing: smooth and progressive transformation of one image into

another – e.g. Transforming a photo of you into a LION

Video: Combines image and sound data together to create information for humans in the form of movies

Like in animation , the illusion of movement is created by displaying images one after another in sequence

HARDWARE FOR CREATING AND DISPLAYING MULTIMEDIA Video Cards: An interface between the system bus and a screen Cathode Ray Tube (CRT): Specialised vacuum tube in which images are

produced when an electron beam strikes a phosphorescent surface Liquid Crystal Display (LCD): Electrical and Optical device used to display

digits, characters and images (Uses Light) Plasma: Plasma is the fourth state of matter and it is formed when Gas is

heated (like Gas is formed when liquid is heated). Plasma Televisions consist of this matter, and what is displayed in each pixel on the Plasma Television is determined by the way this matter is being manipulated

Touch Screen: A computer display screen that is sensitive to human touch, allowing a user to interact with the computer by touching pictures or words on the screen (3 Types: Resistive, Surface Wave, Capacitive)

Digital Projectors: Use a strong light source to project images onto a screen Sound Card: A device that converts digital sound into analog sound, and

vice versa Speakers: Analog devices that convert an alternating current into sound

waves Headsets: A combination of a microphone and a speaker in a single device Head-up Displays: A transparent screen where the user can view critical

information while keeping their head up and looking forward at what is going on in front of them

Optical Storage: Retrieving data from an optical disk can be split into two processes – spinning the disk as the read head assembly is moving in, or through reading and translating reflected light into electrical signals

SOFTWARE FOR CREATING AND DISPLAYING MULTIMEDIA Presentation Software – e.g. Microsoft PowerPoint Word Processors – Including sound and video, such as through => embedding

and linking Authoring Software – e.g. Adobe Flash CS3 Professional Animation Software – e.g. Xara3D HTML Editors and Web Browsers – e.g. Microsoft Internet Explorer

EXAMPLES OF MULTIMEDIA SYSTEMS Education and Training – e.g. Multimedia Tour of IE 7 Tabbed Browsing Leisure and Entertainment – e.g. MMO Games, Action Games Provision of Information – e.g. Information Kiosks Virtual Reality and Simulation – e.g. Aircraft Flight Simulators

EXPERTISE REQUIRED Content Provides – Provide content which is ready to be used System Designers – Work through the stages of the SDLC (e.g. Identify the

purpose, make decisions on the most feasible solution etc.) Project Managers – Develop the project plan and ensure it is followed during

development Writers – Produce textual content in multimedia systems, and create storylines Video Production Personnel – Includes at least a director, camera operator,

sound engineer and a few actors. These videos are then used in presentations Audio Production Personnel – Specialise in the recording and editing audio,

including voice, music and special effects. These sounds are then used in presentations

Illustrators and Animators – Artists who draw figures and scenes Graphic Designers – Improve the readability of multimedia by enhancing the

visual appeal of the presentation Technical Personnel – Ensure the final system will operate correctly on the

users machines

INFORMATION PROCESSES 1) ORGANISING

Organising can be seen in multimedia systems in STORYBOARDS: A storyboard is an illustrated scene-by-scene layout of the multimedia

presentation. There are 4 main types: Linear Storyboard: sequential movement through the project

Hierarchical Storyboard: top down approach - users have multiple choices at some stages

Non-Linear: the user can choose the path of the navigation through the project – NO restrictions!

Composite: aspects of all three types (shown above) are incorporated

2) COLLECTING Collecting can be seen in multimedia systems through collecting the raw

analog data, and then converting it into digital data Flatbed Scanner: Collect light as their raw analog data, and transform it into

binary digital data – Also involves ANALYSING, ORGANISING AND PROCESSING

Digital Camera: Combine image collection with audio collection, and have transformed the photographic process since recording has been replaced by electronic and digital processes

Microphone: Collects data in the form of sound waves, and converts these waves into electrical energy

Video Camera: Combine image collection with audio collection, using traditional mechanical and chemical processes

Analog to Digital Conversion: Repeatedly sample the magnitude of incoming electrical current, and convert these samples to binary digital numbers

3) STORING AND RETRIEVING Storing and retrieving can be seen in multimedia systems through the number

of different file formats which are used to store information in multimedia production:

Note: There is NO compression in Vector Images (e.g. PDF, SWF, WMF etc.) => ONLY in Bitmap Images

AUDIO: MP3 (lossy), MIDI (lossless or none), WAV (either, or none) VIDEO/ANIMATION: AVI (usually lossy), MPEG (lossy), Animated GIF

(lossless), FLV (lossy) BITMAP IMAGE: JPG (lossy), TIFF (lossless), BMP (lossless), GIF

(lossless)

4) PROCESSING Processing can be seen in multimedia systems through the creation of the final

multimedia presentation using a suitable software application

Software such as Microsoft PowerPoint would be used to produce slideshow presentations, and can combine, manipulate and link multimedia content (processing is the manipulation of data), e.g.:

1) Import existing content into the application (through a library, or a collection of media created by the application)

2) Create screens, add and format content, and create hyperlinks 3) Create the final file or files for distribution and display

ISSUES Copyright: Copyright laws are used to protect the legal rights of authors of

original work Integrity: It is common in multimedia systems to have content derived from a

variety of sources, and makes the job of verifying the correctness of presented information more difficult. As a result, it is important to reference all data to ensure its accuracy

Emerging Trends: Virtual worlds is a good example – an online simulated environment where people take on another persona using avatars

Information Systems and Databases - *Syllabus Notes

Information systems

Characteristics Organisation of data into meaningful information Analysing information to gain knowledge

Types & purposesTransaction processing systems (TPS)

Collects, stores & modifies transactions of an organisation Provides data to other systems E.g. credit card systems, EFTPOS, POS terminals

Management information systems (MIS) Takes data & organises it into information reports (usually from TPS) Provides information on the performance of an organisation E.g. Execute information systems (EIS) – strategic issues

Decision support systems (DSS) Takes data (usually from TPS, MIS & external sources) to assist in decision

making Provides analysis tools, information & models E.g. in statistical analysis, stock market, trade figures

Office Automation System (OAS) Manages vast quantities of data within an organisation Improves efficiency, effectiveness in completing administrative tasks Software & communication technology e.g. voicemail, word processors,

spreadsheets

Database Information Systems

School databasesEnvironment

School community (students, staff, parents) Authorities e.g. BOS, government Any organisation, business, or individual that receives information generated

by the school or supplies data for the systemPurpose

To maintain the efficient operation of the school, personnel, resources & administration tasks

To provide information on student enrolments, subject selections & assessments for both school staff & educational authorities

Data/Information Information on people, resources & processes Equipment registers, finance & purchase orders, library loans, staff

information, timetables, student marks & gradesParticipants

Office & library staff who enter data Teachers

Information technology Computers Barcode readers Scanners Software- spreadsheet applications

RTA systemsEnvironment

Drivers, instructors, examiners Vehicle owners, vehicle inspectors Gov departments e.g. NSW department of transport Police & courts

Purpose To manage registration of all drivers & motor vehicles in NSW To provide information to drivers/applicants on matters such as licensing,

vehicle registration etc as well as statistical information to government & other authorities

Data/information Drivers’ details – contact, payment, driving history, license information Vehicle owner details – registration numbers, payment, inspection records

Participants Data entry operators Administration staff at offices Inspectors Police department- traffic branch

Information technology Computers Cameras Barcode scanners Networking between computers

Video stores’ systemsEnvironment

Customers & staff Suppliers Other chain stores, head office

Purpose To keep accurate records of the stock (rental & sales) To collect data for further analysis by store management

Data/Information Customer details (current loans, overdue items) Rental records (in stock/on loans) Saleable item records (videos, snacks) Rental/Sales figures

Participants Staff who check out videos & other products, process returns, authorise orders

for new stock Head management

Information technology Computers Barcode scanners WAN link from head office (update new rental titles) DB management & sales software Network communication software

Organisation

Non-computer methods of organisingExamples

Filing cabinet e.g. small businesses Telephone books Card catalogues e.g. libraries Reference books e.g. encyclopaedias

Advantages No specific skills or training required Inexpensive Highly portable & lightweight Don’t require power supply/batteries

Disadvantages Access/organisation is usually by one method (e.g. alphabetical) Inflexible layout 1 person only can access at one time Easily misplaced

Computer-based methods of organisingExamples

Flat file systems Database management systems Hypermedia

Advantages Easily exchanged between applications & over networks Easily edited Much faster processing Large storage of data

Disadvantages Costly Exchange of data on a network creates security & confidentiality problems

Logical organisation of flat file databases Single table of data stored as a single file All rows (records) are composed of the same sequence of fields (attributes) Allows you to use & manage 1 database at a time

Files Block of data which is divided into a set of related records

Records Collection of facts about one specific entry in a database Organised in rows Divided into 1 or more related fields

Fields Specific category of data in a database Made up of characters Organised in columns (attributes)

Key fields Used to uniquely identify a record in each file Used to sort & retrieve information Usually, each key holds a unique item that applies to only one record Convenient- when sorted not all data has to be read/retrieved

Characters Single unit of data used in a database E.g. letter or symbol

Logical organisation of relational databases Organises data using a series of related tables, linked by common keys Draws information from one or more additional files

Schemas Organised plan of the entire database Shows how & where data is found, description of data, data relationships Entities- specific title of which attributes are detailed under e.g. customer,

orders Attributes- Defined property of an entity e.g. CustID, Firstname

Field names, same as fields in a flat file database Relationships- the way entities relate to each other

One to many: one record in the 1st entity relates to many records in the 2nd entityOne to one: one record in the 1st entity relates to 1 record in the 2nd

Many to many: each record in the 1st entity relates to many records in the 2nd

Tables Implementation of entities Attributes

Records Linking tables

- Primary key: uniquely identifies a record (field or combination of fields)- Foreign key: Attribute of a table that is a primary key of another table

Data modelling tools (for organising databases)Data dictionaries

Describes characteristics of data- metadata Field name Data type

-Alphanumeric: letters/numbers/symbols-Numeric: numbers & numeric symbols-Boolean/logical: true/false, yes/no-Date data: dd/mm/yy-Time data: hh/mm

Data format Field size- number of characters allowed in the field Description- explains contents of the field Example- illustrates content

Schematic diagrams Graphical tools that help define the database E.g. ERD – determines data to be included/excluded

Normalisation Reduces data redundancy by removing repeating fields or reorganising data

where needed, hence improving performance Avoids inconsistencies among values Analysing data to create the most efficient database structure

Logical organisation of hypermedia Storage/linking of media & documents May contain text, numbers, images, audio, animation & video Each document is independent & can be retrieved electronically using

hypertextNodes & links

Nodes: Computer that has destination of the link Links: Links nodes in a hyper document- associated with bookmarks &

anchorsUniform resource locators (URL)

Address of file/resource on the web Protocol: allows access to web pages based on hypertext- ‘http’ Domain name: address of specific computer where resource is located

‘www.whatever.com’ File path: path followed to the file being retrieved

HTML tags (hypertext markup language) Metadata- information about data Indicates how parts of a document are displayed & navigated Viewed as pages in web browsers

Tools for organising hypermediaStoryboards

Series of frames, each representing a different action or screen image Consists of navigation paths, information & graphics Linear: sequential path Hierarchical: choices branch off into further choices, based on navigation Non-linear: no structure- free navigation Composite: mix of all layers

Webpage creation software Allows text, graphics & sounds to be hyperlinked HTML tags inserted automatically by the software

Storage & retrieval

Database management systems (DBMS) Software application that allows the entry, manipulation & storage of data in a

database Handles access to the database- establishes & maintains data security by

restricting access to authorised personnel Carries out validation & verification of data Independence of data from the DBMS

Access of dataSequential

Each record must be accessed in a linear progression, from 1st to last E.g. accessing data on magnetic tape

Direct Data is accessed in any order i.e. without accessing previous data items E.g. storing data on disc & logical location of data within a database

StorageOnline

Storage device permanently positioned Available immediately to connected computers E.g. hard drive, CD & DVD juke boxes

Offline External devices used to store data Cannot be accessed until storage media is mounted into a drive E.g. USB, CD ROM, DVD, memory cards, magnetic tape

Storage mediaHard discs

Stores data magnetically on precision aluminium or glass platters Direct access

CD-ROMs Data is read & written using laser technology Direct access

Cartridges Magnetic tape encased in a cartridge If it is linear -> sequential

If it is non-linear -> directMagnetic tape

Stores large amounts of data inexpensively Used for backup Sequential access Erasable, reusable

Encryption/decryptionEncryption

Process of encoding data -> maintains confidentiality & security Algorithm or key is required to encode the data Involves manipulations of bit patterns

Decryption Process of decoding data -> receiver can translate Reverse algorithm or key is required to decode the data

Asymmetric Requires public key for encryption & a private key for decryption

Symmetric Same key required for encryption & decryption e.g. DES

Backup & security procedures Storing/copying data to another permanent storage device Physical security measures- locking rooms/buildings Usernames & passwords Encryption/decryption Restricting access using DBMS views Record locking

Centralised & distributed databasesCentralised

Accessed through a single DBMS server Single database All users connect directly to DBMS

Decentralised/distributed Set of connected databases stored on multiple computers Appears as 1 large database to users

Tools for database storage & retrievalSearching & sorting

Carried out on a field alphabetically, numerically or chronologically -> relevant information is extracted

Query by example (QBE) Operator enters criteria against a field Records meeting specific conditions are displayed

Structured query language Specialised language designed to search a database Manipulates display of data in a search- more specific Commands

- Select: fields i.e. data to be displayed

- From: tables i.e. source of data- Where: criteria i.e. query- Order by: fields i.e. order in which fields are to be displayed

Tools for hypermedia search & retrievalFree text searching

Technique for searching a computer based document or database for characters or words

Search engine searches all words and tries to match search words supplied by the user

Search engines Indexing- databases of indexed websites that can be searched using keywords Search robots- programs that facilitate indexing by accessing websites &

gathering information Metadata

Reporting on data found in hypermedia systems Web browsers Stand alone applications Media players

Other information processes for databases

Displaying Reporting- formatted & organised presentation of information

E.g. mailing labels, invoices, sales summaries & telephone lists Constructing different views of a database for different purposes e.g. form-

used to enter, view & edit data

Issues related to information systems & databases

Acknowledgement of data sources Permission from source to use data before publication Data source acknowledged Ensures justification of outputs e.g. results from surveys Provides a mechanism for tracking & auditing data -> determines accuracy of

data Requirements of source organisation Legal requirements- copyright Gives company credibility

Access to, ownership & control of data Limited access to authorised personnel only -> control over data Prevents: unauthorised access, alteration/destruction of data or programs,

unauthorised use of resources & release of informationFreedom of Information Act (Federal)

Allows individuals to obtain access to information held as records by the government, request amendments to records, appeal against decisions not to grant access to information or to amend personal records

Information such as school, health, superannuation records (personal) government policy documents, research materials, product testing records

Agencies/public bodies- unis, public hospitals, ministers, government departments

Exempt information- personal affairs of another person/business, the economy, law enforcement

Privacy principles Protects an individual’s personal information e.g. health, racial, criminal,

financial Security measures to prevent unauthorised access into the system & the

release of personal information Organisations/corporations must abide by these principles to maintain legal

compliance and ethical reputation

Accuracy & reliability of data System must be able to resist user mistakes, system malfunctions, deliberate &

accidental alteration Error detection & correction methods Data bias- the way the data is collected, interpreted & manipulated Accuracy of data sources e.g. Wikipedia very unreliable, BOM reliable

Quality of data Data must be fit for its intended use i.e. to fulfil the needs of its users as well

as suitability for applications

Data matching to crosslink data across multiple databasesCurrent & emerging trends (organisation, processing, storage/retrieval)Data warehouses

Stores raw data which is collected electronically from a variety of sources Data may be available for sale to interested parties -> privacy issue e.g.

medical records, credit cards etc E.g. real estate agency may buy information from council

Data mining Process of searching through data, trying to match any patterns e.g. customers

with common interest Security issue e.g. centralising personal information into 1 warehouse

Online analytical processing (OLAP) Provides statistical evidence to corporations -> assists in decision making

Transaction Processing Systems - *Syllabus Notes

4.1 Characteristics of TPS’sA Transaction Processing System is a system that collects, stores, modifies and retrieves the transactions of organisations. A transaction is an event that generates or modifies data that is eventually.

4 main characteristics

Components of TPSo Purpose : What is it’s overall aimo Data : Raw factso Information Technology: Hardware and Softwareo Processes: o Participants: People involved in the operation of a system

Batch Processingo Batch Transaction Processing involves collection and storage of data

as a batch. The batch is then processed later at a scheduled time (i.e. there is a time delay)

o Transactions will be stored (usually on magnetic tape or paper) until it is convenient or economical to process them

Real Time Processing (e.g. airline reservation systems and banking TS’s)

o Real Time transaction processing is the immediate processing of datao It provides instant confirmation of a transaction but does not require

access to an online database.o Two main concerns

Concurrency Ensures that no two users can change the same data at

the same time

e.g. if a ticket is starting to be reserved by an airline agent, another agent cannot tell another passenger its available

Atomicity Ensures that all the steps involved in a transaction are

completed successfully as a group. If any step fails no other should be completed.

E.g. in a bank transfer, if the withdrawal succeeds, the transfer must also succeed, otherwise the entire transaction is abandoned.

Differences in Batch and Real Time

o Each transaction in real time is unique; it is not part of a groupo Real time requires the master file to be available more often for

updatingo Real time has fewer errors as data is validated and then entered

immediatelyo With batch, errors can occur when data is organised and storedo More computer operators are required in real time

Data validation in TPS’so Data validation involves checking of data as it is entered into a systemo Data validation is critical in transaction processing as inaccurate data

will have dire consequences on the completion of a transactiono Methods of Validation

Range check (e.g. Date of birth from 1900 to current) List check (e.g. drop down boxes) Type check (e.g. Integer/Boolean) Check digit (perform addition arithmetic, obtain chckdigt)

Historical Significance of transaction processing systems as the first type of information systems

o TPS’s were used during the 1950s (UNIVAC was first one)o These formed the basis for further development of TPSso Manual transaction systems are business systems that operate without

the use of machineso Computerisation of manual transaction systems provided large benefits

4.2 Types of TPS’s Users/Participants/People

o Users are people that receive an output from the TPSo Participants are people that conduct the information processingo People from the environment are becoming participants as they

directly enter transactions and perform validation Different types

o Web basedo Non Web basedo On-line Real Timeo Batch

Examples of RT systemso Reservation systemo Point of Sale terminalso Library loan system

Examples of Batch systemso Cheque clearanceo Bill generationo Credit card sales transactions

Systems that appear real time (respond as the transaction occurs) but are actually updating in batch (EG Credit card transaction)

4.3 Storing and retrieving in TPS’sA TPS requires an efficient method for the storage and retrieval of data. Data is normally stored in a database or data warehouse and requires well designed backup and recovery procedures.

Storage of digital data in databases and fileso A database is an organised collection of data

Hierarchical: Series of levels with a top down structure Network: Series of nodes connected by branches Relational: Uses related tables to build relationships

o Database Design Features Good data placement: Place frequently accessed data close Short transactions: short transactions enables quick processing Real time backup: Do backups at low access times High normalisation: Keep redundant data to a minimum Archiving historical data: Archive rarely used data Good hardware configuration: Good hardware = quick response

o A file is a block of data, which, in databases, is divided into related records, fields and characters

Retrieval of stored data to conduct further processing (printing invoices) Systems to store paper records of transactions

Data backup (copy of data used to rebuild a system) and recoveryo Grandfather, Father, Son

Grandfather, father, son is a traditional system of backups that stores the latest backup and the two previous ones.

Each time a new backup is made it becomes the “son”, and the previous “Son” becomes the “Father” and the previous “Father becomes the “Grandfather” and the previous “Grandfather” is either archived or recycled.

o Off site storage Offsite refers to a location which is physically separated from

the main system, and hence, off-site storage is storage of data on magnetic disks or Removable hard disks at an Employee house etc.

o Secure on-site storage On-site refers to a location is that is physically close to the

system, and hence, Secure on-site storage refers to the storage of data through the use of hard disks etc.

Secure On site storage provides faster access to the backup data but requires extra precaution and is more risky than “off site storage”.

o Full and partial backups A Full Backup involves copying all files. It is usually done

weekly or monthly A partial backup involves copying files that have been created

or changed since the last backup, which reduces the backup time tremendously and therefore can be done daily.

Partial backups are broken up into; Differential: All the files that have changed since the

last full backup Incremental: All the files that have changed since the

last full or partial backupBackup Procedure Advantages DisadvantagesIncremental Faster, uses less space The full backup and the

daily backup has to be loaded to restore all the data

Differential The full backup and only the last daily backup have to be loaded to store all the data

Slower than incremental, each backup needs more space

o Recovery testing Recovery testing is the process of testing a backup after is has

been made by restoring files into a temporary directory Backward recovery undoes unwanted changes Forwards recovery beings with the backup copy and processes

all transactions from the partial backups in order through to the current.

o Suitable media Storage media ranges from floppy disk to magnetic disks, to

CDs, DVDs, Hard disks and Zip disks etc Even though magnetic tape is slow and sequential, it is

inexpensive and often used for backups See table 4.5 Page 164 Jacaranda for more information

o Specialised backup software Specialised backup software provides considerable control over

the backup and restoration processes by; Combining full and partial backup procedures Providing backups of selected files Selecting files for backup by date/size/type Providing optimal compression Providing unattended backup Scheduling backups, Encrypting backups, Logging

backupso Transaction logs

Transaction logs record events that have occurredo Documenting backup and recovery procedures

Recovery o Mirroringo Roll back

A roll back is the process of converting the current system back to its old system, or going from a son backup and loading a father.

Data warehousingo A data warehouse is a database that stores large amounts of

information from

o Data mining is the process of analysing large amounts of data to reveal hidden patterns or relationships

o Updating in batch systems (no considerable user interaction)

o Historical significance Paper record systems were collected in batch and transactions

were updated on a fixed basis. When punched cards/tape was only available, updating was

considerably timely and expensiveo Limitations of batch processing

Usually time consuming due to the use of sequential storageo Technology required

Hardware includes large storage capacity media (must be sequential)

Software does not have to allow for online work or a simple user interface as only well trained and experienced participants use it.

o Steps in batch update All changes are made to the transaction file and stored The transaction file is sorted by a key field in the same

sequential order as the master file The files are matched by the key field and the relevant records

in the master file are updated o Suitable applications

Updating in on-line real time systems (requires considerable user interaction)

o Relevance and impacto Technology required

Hardware includes large storage capacity media (must be direct access so response time is very quick

Software must enable online work for multiple simultaneous use (provide access to an online database)

Software must include a user friendly interface as many participants will use it

o Steps in on-line real time processing Read the key field from the transaction file record Using a mathematical procedure or algorithm (such as the hash

storage calculation), the location of the same record in the master file is found

If the master record Is being used, wait until it is finished Update the master record by overwriting with the old record

o Notes Requires considerable interaction with the user Requires user friendly software (possibly online help) Requires real time data validation Requires direct access storage to access data quickly

4.4 Other information processes in TPS’s CollectingCollecting from a TPS involves generating the transaction data

o Hardware MICR (Magnetic Ink Character Recognition)

MICR systems are used by banks to read account numbers on cheques

Characters are printed using magnetic ink that contains magnetised particles

ATM (Automatic Teller Machine) An ATM is a banking terminal for common transactions

Barcode Readers Barcode readers are used in retail industries to collected

product information and point of sale The reflected light off the barcode lines identifies the

prod.o From forms (Form: a document used to collect data from a person)

Paper Form: Written on to provide data and then processed Onscreen Form: Usually completed for data entry to populate

DBs Web Form: For users wanting to purchase products off the

interneto Screen design for online data collection

Drop down menus, radio buttons, command buttons, check boxes

Use of colour, alignment, white space, images etc

Analysing data, in which output produced is used as input in other systems

The results of processed transactions are stored in a database and are analysed in ways to meet the information needs of users.

o Decision support systems DSSs assist people in making decisions by providing

information, models and other analysis tools. For example, a business may use a TPS to process its sale

transaction, and then use a DSS to summarise its sales by date/region/product. This information will then be used for decisions

Data mining is used in DSSs to find relationships and patterns in data stored in a database

o Management Information Systems MISs provides information about basic facts such as sales

performance, payroll, and budgets. The MIS shares the data from a TPS, which is then manipulated

to create reports (Scheduled reports, forecast reports, on demand)

4.5 Issues related to TPS’sBoth positive and negative issues arise from TPSs

Changing nature of worko Automation of jobs once performed by clerks

Automation of jobs refers to the use of information technology to perform tasks once done by people

Workers are required to learn new skills and complete ongoing training or face being replaced by a more skilled worker

This can either result in extra stress on workers or increased happiness

Information systems can expand the scope and significance of a users job or they can reduce it (affects meaning of work)

o Shifting of workload from clerks to members of the public TPSs allow every user with access to a terminal to enter and

retrieve data, which is what a clerk would have done Need for alternative procedures when the TPS is unavailable

o Blackouts or breakdowns can completely disable some TPSs and businesses must plan for such times.

o Non-computer procedures must be in place, and these must have been checked and tested

Bias in data collectionBias means that data is unfairly skewed to a particular result or direction.

o When establishing the system and deciding what data to collect Data collection methods should be specified carefully Loaded questions must be avoided in questionnaires or web

formso When collecting the data

Adhere to protocols established earlier. ‘random sampling’ does not apply to web surveys as not

everyone has the internet Importance of data in transaction processing

o Data security

Data security protects a systems data against accidental or deliberate damage

Passwords and biometric methods (fingerprints etc) Encryption Firewalls

o Data accuracy Data accuracy is the correctness of the data (extent to which it

is free of errors) Errors can occur;

Data collection errors : Poor handwriting/badly worded questions

Data entry errors: Typo’s Out-of-date errors: Person’s data changes (move etc) Mismatching errors: Data relates to a similar person,

maybe with a different nameo Data integrity

Data integrity is the reliability of data, it involves accuracy, currency and relevance of the data

In real time transaction processing, data integrity is achieved when the ACID test is passed

Atomicity: All steps of a transaction are completed together

Consistency: Correct programming, such as always debiting and crediting the correct account

Isolation: Ability for transactions to be processed at the same time as others, but still behave independently

Durability: Changes become permanent when committed

Control in transaction processing and the implications for participantso Controlling transaction processing starts with collecting and includes

the way the TPS manipulates the data and the way errors are corrected.o People should not become completely dependent on a TPS. They need

to maintain control over their organisation’s operationso Due to the immense volume of data errors are caused, and if no control

measures are taken these errors will be unnoticed and have dire effects on the transaction, the transaction system and the organisation.

Current and emerging trends in transaction processing

End of Study NotesBy Chromatic