CHAPTER 1 - SYSTEM FUNDAMENTALS Flashcards

1
Q

System life cycle

A

The stages through which the development of a new system passes through

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2
Q

5 stages of system life cycle

A

Analysis, Design, Implementation, Operation, Maintenance

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3
Q

Why is new system created

A

To replace inefficient old system, fix default/defects, increase quality of output/productivity of the system

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4
Q

Requirements needed for a new system

A

Internet, RAM, operating system, hardware, software

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5
Q

Limitation of new system

A
  • end users not being able to use the system properly
  • data migration is time consuming
  • memory issues and data clashes when system is developed/tested
  • maintenance is costly overtime
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6
Q

Potential organizational issues in planning of a new system

A
  • lack of attention to required training
  • lack of attention to organizational issues
  • lack of stakeholder and end-user participation
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7
Q

Whats a feasibility study

A

study that evaluates and analyzes a project and its potential based on TELOS criteria: Technical, Economical, Legal, Operation and Scheduling

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8
Q

Planning

A

process of thinking about various details and organizing the activities required to achieve the desired goal

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9
Q

Whats TELOS criteria

A

Technical: Is existing technology appropriate to implement proposed system
Economical: Is it cost-effective
Legal: Is it against any laws/regulations
Operational: Is existing organizational practices sufficient to maintain and operate system
Scheduling: How long will we wait

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10
Q

What is change management

A

Involves various parameters and is the process of shifting existing individuals, teams and departments from an existing to desired state; goal is to maximise benefits and minimize negative impacts of the change on individuals

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11
Q

What is a legacy system

A

Old technology, hardware or computer system

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12
Q

Why are legacy systems still used

A
  • Data cannot be converted to newer formats/applications cannot be upgraded
  • System provides users needs even if newer systems exists
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13
Q

Outline one problem of maintaining legacy systems

A

Continuous patching, updating and upgrading of the old system to look out for any bugs/errors

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14
Q

4 strategies to integration

A
  • Replace both information systems with a new one (high initial cost)
  • Keep both information systems and develop them to have the same functionality (high maintenance cost)
  • Select one company’s computer system and discard the other (policy problems)
  • Select best info system from each company and combine them (workers may have difficulties working with a system from another company)
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15
Q

Software incompatibility

A

a situation where 2 different software systems cannot operate cooperatively/individually in a same computer or different computer linked by a LAN/WAN (network)

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16
Q

SaaS “Software as a Service”

A

a contemporary delivery method that allows software and data to be hosted & managed centrally on a remote datacenter.
Example: Powerschool/Netflix; basically just a software that offers a service

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17
Q

Features of SaaS

A
  • Subscription: users have to pay to access services provided
  • Uses a multi-tenancy model: single software and its supporting infrastructure can serve multiple customers
  • Uses cloud service to store customer data (which reduces data loss risks)
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18
Q

Limitations to SaaS

A
  • Possible data loss if SaaS provider goes out of business
  • Involvement of a third party i.e. SaaS provider which risks user data privacy
  • Uncertainty of data’s location: customers have lower access to their personal data; usually stored away in datacenter
  • Risk of identity theft: the providers often require credit card payments for subscription; may not provide better identity management security/poor firewall
  • Connectivity requirement: SaaS model is based on web delivery, if internet service fails, loses access to software data
  • Access management: if design of the access control system is inefficient, a single act of accessing the cloud service can expose confidential data
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19
Q

Distinguish between Phased and Direct changeover

A

Phased conversion method is when the new system is implemented/introduced per module to the whole company. If the particular program/module is proven satisfactory, another module will be introduced until the system is introduced completely. With this approach, the training period is extended and the adoption of the new system takes longer since it is implemented separately at different times. On the other hand, direct changeover is very risky since the company replaces their old system with a new one immediately. With this approach, all users require proper training before the switch takes place, in order to use the new information system efficiently.

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20
Q

Direct/Big Bang changeover

A

instant from old to new

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21
Q

Parallel changeover

A

old and new is run side by side; only when output of new is proven satisfactory then the old system is terminated

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22
Q

Pilot changeover

A

the whole system is introduced to one branch/department of the company and its performance accessed before being introduced elsewhere in the company

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23
Q

Phased changeover

A

the new system is introduced per module to the whole company, only when its proves satisfactory then the next part is introduced - until the old system is fully replaced

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24
Q

Data migration

A

transfer data between different formats, storage types, computer systems; It usually takes place when a business changes, upgrades, or merges its computer systems

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25
Q

Possible problems during data migration

A
  • Data loss: due to incomplete data transfers/ errors because of differences in International conventions concerning data time and measurement units
  • Data incompatibility: information during data migration may not retransferred due to parameters such as incompatibility with the new systems/non recognizable data structures
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26
Q

2 types of main testing

A

Functional testing = test whether or not the features of the program (menu functions, individual commands, text input) perform according to design specifications. For example, the programmer wishes to test if the system’s function “add to client” brings them to the add client module

Data testing = involves using normal, abnormal and extreme data to test the system. For example, normal data “75” is used to test whether or not the output of the school’s marking system (with 60 as the middle range) will show “pass” or fail” messages appropriately

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27
Q

Alpha testing

A
  • Testing the software before the product s released to public
  • Tests by the company in lab type environment and not by end users in their usual workplaces
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28
Q

Beta testing

A
  • include comments and suggestions from end users
  • their feedback valuable to fix defects/errors of the program & contribute to the preparation of support teams who will deal with expected problem
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29
Q

Dry run test

A

conducted using pen-paper by programmer; run the algorithm mentally and decides on what the output of a run should be (execution)

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30
Q

Unit test

A

individual parts of the system are tested seperately

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31
Q

Integration test

A

entire system is tested at the same time to verify that all components work together

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32
Q

User acceptance test

A

determine if system meets user needs and conducted within the users premises before accepting transfer of ownership

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33
Q

Debugging

A

process of identifying and correcting errors/faults in a new system

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34
Q

Business merger

A

combining 2 or more businesses into a single corporation

35
Q

Internal documentation

A

code comprehension features and details provided as part of the source code itself; example: appropriate module headers, appropriate code indentation, appropriate code structuring

36
Q

External documentation

A

written as a separate document from the program itself; provided through various types of user supporting documents; user guide, software requirements specification document etc

37
Q

Methods of providing user documentation

A

manuals, email support, live chat sessions, FAQs

38
Q

Methods of delivering user documentation

A

online training, formal classes, self study

39
Q

Data loss

A

error-condition where data is lost or destroyed due to system failure, storage negligence, or even transmission or processing errors

40
Q

Methods to prevent data loss

A

regular backup of files, firewall installation, antivirus program

41
Q

Reasons for data loss

A

Accidental deletion, building fires, computer viruses

42
Q

Types of removable media used as fast data backups

A

Blu-ray discs, CDs, DVDs, USB

43
Q

Failover system

A

a computer system which is on standby capable of switching to a spare computer system upon hardware, network failure or software malfunction; automatic and handles abnormal situations without human interference

44
Q

Patches

A

used by software companies to update applications by fixing known bugs and vulnerabilities

45
Q

Upgrades

A

contain novel/complex functionalities or characteristics, as well cumulative bug fixes

46
Q

Updates

A

improves a product in a minor way by adding new functionalities or fixing known bugs

47
Q

Releases

A

final, working versions of software applications

48
Q

software

A

programs that control computer system/set of instructions guiding computer to perform specific tasks

49
Q

hardware

A

physical elements of a computer

50
Q

peripheral device

A

any auxiliary device that can communicate and work with a computer; extends capabilities of the computer system it is connected to

51
Q

computer network

A

a set of computer systems that are interconnected and share resources and data

52
Q

human resources

A

people who are used in an organization

53
Q

firewall

A

hardware or software network infrastructure that controls data flow access among network entities

54
Q

client

A

receives data via the network; average computer/terminal used to access a computer-based system

55
Q

Domain Name System Server

A

attributes names to network addresses and therefore resolves names by assigning them to appropriate network entity; allows you to types names in to address bar of your web browser “mit.edu” then the web browser automatically finds that address on the Internet

56
Q

server

A

program/computer that provides services requested by clients connected over a network

57
Q

MFA (Multi-factor authentication)

A

authentication technique used to control computer access; authentication factors:
- something you know = passwords
- something you have = ATM cards
- something you are = biometrics

58
Q

IT subjects of social and ethical significance

A
  • reliability = how well an IT system functions
  • security = protection of hardware, software, and computer networks from unauthorized access (biometrics, proprietary tokens, passwords etc)
  • digital divide and equality of access = growth and use of IT systems have not developed at the same rate for all countries; even in advanced countries there are people who lack access to IT infrastructure
59
Q

Stakeholders; mention the examples

A

Individuals, team, groups/organizations that have an interest in the realization of a project/affected by the outcome; e.g. end-user, manager, specialists, frequent user

59
Q

Advantages and disadvantages of students having unrestricted access to PC

A

pros:
- allows students to learn at their own speed
- allows students to access information to help with their studies

cons:
- some sites do not give accurate information
- some sites encourage and facilitate illegal/inappropriate activities

60
Q

Methods of obtaining requirements from stakeholders

A
  • questionnaires
  • interview
  • direct observation
61
Q

Describe one advantage and one disadvantage of using observations to gather information when planning a new system

A

Advantage: Direct observations makes the collection of different types of data and information possible. This is because the analysts are directly spending time on different departments, facilitating involvement of all activities and processes

Disadvantage: Observations are very time-consuming and expensive as you need to hire specialists to carry them out

62
Q

What are questionnaires? What are closed/restricted and what are open/unrestricted?

A

carefully constructed questions that draw out unambiguous responses; survey methodology = domains of applied statistics that focuses on taking samples from a population and improve various data collection techniques

  • closed/restricted questionnaires:
    short response questions (yes/no), facilitates statistical analysis
  • open/unrestricted questionnaires:
    free response questions, difficult to summarize and make statistical analysis impossible; yield more reliable information
63
Q

What is interview? What is the difference between structured and unstructured interview?

A

direct fact-to-face procedure that focuses on obtaining reliable and valid data in the form of verbal responses from a person/group of stakeholders

structured: strictly standardized; presented in the same manner to each stakeholder

unstructured: flexible; encourage to express their thoughts and personal beliefs freely

64
Q

What is direct observation

A

involves spending time in different departments and show where procedures and processes could be made more efficient or make the collection of different types of data and information possible

pros: familiarizes analyst with the project/case study
cons: time-consuming; hires analyst/specialist (extra cost)

65
Q

System flowchart

A

a way of displaying how data flows in a system and how decisions are made to control events

66
Q

Online processing

A

data processing performed by a single processor through the use of equipment that it controls; e.g. airline reservation

67
Q

Real time processing

A

data processing performed on the fly in which the generated data influences the actual process taking place, e.g. aircraft control

68
Q

Batch processing

A

data processing performed on data that have been composed and processed as a single unit, e.g. payroll

69
Q

2 high-level computer languages that support modularity

A

Java, JavaScript

70
Q

Prototype

A

a working/non-working preliminary version of the final product used as part of the design phase to demonstrate how the final product will work

71
Q

Functions of prototype

A
  • provides just enough of the concept for investors to decide if they want to fund the full production or not
  • helps in the identification of problems with the efficiency or design
  • increases system development speed
72
Q

Iteration

A

repetition of a set of instructions for a specific number of times until operations yield a desired result

73
Q

Accessibility

A

potential of a service, product, device or environment to serve and meet needs of as many individuals as possible

74
Q

Usability

A

potential of a product, application, or website to accomplish user goals

75
Q

Ergonomics

A

design of safe and comfortable products, systems or processes

76
Q

state 2 usability problems

A
  • buttons too small
  • excessive keyboard used may lead to RSI (Repetitive Strain Injury) syndrome
  • bright screens may cause eyesight problems
77
Q

Methods to improve accessibility of systems

A
  • touchscreens
  • voice recognition
78
Q

Environmental implications of interaction between humans and machines

A
  • printed paper waste
  • electronic waste contains chemicals that are harmful for the environment; ends up in landfills
79
Q

Economic implications of interaction between humans and machines

A

digital divide between high and low income households (those who can and cannot afford) -> increased inequality & reduced opportunities for education, entertainment and income

80
Q

Ethical implications of interaction between humans and machines

A

machines make human lazy and overusing can affect our mental and physical health

81
Q

Moral implications of interaction between humans and machines

A

computers carry false information to humans without realising

82
Q

Social implications of interaction between humans and machines

A

concerns that advancements in technology leads to unpredictable and dangerous situations which reduces involvement of humans; cause humans to become enclosed in virtual environments/limiting socialization