IB CS Topic 1: System fundamentals

SaaS (Software as a Service)

software distribution model in which applications are hosted by a vendor or service provider and provided to customers over a network

The four types of changing to a new system

parallel running, pilot running, direct changeover and phased conversion

Parallel Running

both the old and new system run at the same time

Pilot Running

one section of the business is trying out the new software while one keeps using the old one

Direct Changeover

moving straight from the old to new system

Phased Conversion

slowly implementing the new software

User Acceptance Testing

the last phase of software testing in which actual software testers test the software in real world scenarios

Debugging

identifying and removing errors from computer hardware and software

Beta testing

real world exposure for the product to get feedback from users

User documentation

Documentation to support users of computer systems including hardware and software

Methods of user documentation

help files, online documentation, printed manuals

Possible causes of data loss

user error, malicious actions of a third party, theft, viruses/malware, hardware malfunction, natural disaster

Consequences of data loss to individual users

can lose personal information (ex. address, social security number, health information or bank account information)

Consequences of data loss to companies

can lose reputation/customers, may be sued/have to pay fines

Methods of preventing data loss

create a backup, RAIDs (ex. data mirroring), antivirus softwares, physical security

Strategies for managing/releasing updates

automatic updates, manual updates

Hardware

anything within a computer that you can physically touch

Software

collection of programs and instruction that control the computer

Peripheral

devices attached to the computer that allow interation and the exchange of information (ex. keyboard, mouse, screen)

Network

a group of computers connected toether to share resources such as documents and printers

Human Resources

the humans operating the computer

Operating system

help people interact with the computer system and manage how the hardware, programs and data interact

Client

a computer accessing resources hosted by another computer/the server

Server

a computer hosting resources to be shared across the network

Firewall

protects the network traffic, decides what gets access and what doesn't

Benefits of surveys

little time, simple, large amounts of data

Drawbacks of surveys

hard to ask the right questions

Benefits of interviews

detailed information

Drawbacks of interviews

time consuming

Benefits of direct observations

first hand, unbiased information

Ergonomics

the study of people's efficiency in their working environment

Accessibility

how the system can be accessed for information exchange and operation

Ways to improve the accessability of a system

touch screens, voice recognition, text to speech, braille keyboards, braille printers

A system

is a set of interacting parts that operate together to achieve some objective or purpose.

The three stages of a System

Input Process Output

Things organizations need to consider when changing computer systems

needs, limitations, user roles, cost, underlying technologies.

Why change management is required

Accomplishes change in the most efficient manner while minimizing the impact on an organization.
Provides training and support for staff.
Ensures that a consistent approach to change is used.
Ensures that proper planning, designing, and testing of proposed change has occurred.
Lowers the total cost of IT services.

A legacy system

is an outdated computer system, programming language or application software that is used instead of available upgraded versions

Legacy system compatibility issues

Will legacy software run on new hardware?
Is the format of the legacy system data compatible with new software?
Can the legacy system be used with new technologies?

Business merger compatibility issues

Is the data from each company compatible?
How is the data from each system going to be integrated?
Transformation of data from one system to another.
Companies may not be using same application software.
Businesses may not have same change management policies.