Computer science topic 1- System fundamentals

Data gathering

The process of investigating and researching current systems through methods such as interviews, questionnaires, document collection, and observation.

Interview

A data gathering method that provides detailed information through two-way communication with key individuals.

Questionnaire

A method of data gathering designed to quickly reach large audiences, allowing for extensive analysis.

Document collection

A process of gathering objective data about the inner workings of a system, such as inputs and outputs.

Observation

A method of data gathering that provides first-hand and unbiased information, though it may influence behaviors.

Requirements specification

An analysis phase that identifies the inputs, processes, outputs, and problems of a system to guide new system development.

Change management

A structured approach to transitioning individuals and organizations to a desired future state.

Compatibility issues

Challenges that arise when older systems (legacy systems) or different systems interact, often requiring data reformatting or causing errors.

Legacy system

An older computer system or software that may be incompatible with newer technologies, leading to issues such as data loss.

Cloud computing

The delivery of computing services over the internet, offering models like IaaS, PaaS, SaaS, and NaaS.

Direct installation

A system installation method where the old system is replaced entirely by the new system with no overlap.

Parallel installation

A method where both the old and new systems operate concurrently, allowing for a comparison of outputs.

Pilot installation

A trial of the new system in a small part of the organization before full-scale implementation.

Phased installation

An installation method where the new system is introduced gradually, replacing parts of the old system.

Data migration

The process of moving data from one system to another.

Incompatible file formats

File types that do not match between systems, which can cause data loss during migration if not handled properly.

Validation rules

Rules that ensure the accuracy and consistency of data, which can become incompatible during migration.

Incomplete data transfer

A common problem during data migration where not all data is successfully moved to the new system.

What is an advantage and disadvantage of using an Interview for data gathering?

Pros- Detailed info, two way communication and face to face

Cons- Time consuming

What is a advantage and disadvantage of using a Questionnaire?

Pro- Data can reach large audienecs quickly and can be used to create extensive analysis. Fast and effective

Cons- Has to be well designed otherwise people may not answer properly or completely

What is a advantage and disadvantage of Parallel Installation?

Pros- If new system fails old system serves as backup (safety net), outputs from both systems can be compared to see if new one is running properly

Cons- It is costly and time-consuming.

What is a advatnage and disadvatange of Direct Installation?

Pros- Minimal time and effort, new system is available immediately

Cons- There is no replacement or backup system to fall back on immediately.

What is an advantage and disadvantage of the Observation method?

Pros- First hand and unbiased information

Cons- Observing may influence things or peoples behaviour leading to unrealistic results

What is an advantage of Phased Installation?

Users can get used to the new system in small stages, and training can be completed gradually rather than all at once.

Cloud computer advantages vs disadvantages

Pros- Convenience, security, backups, collaboration and environmentally friendly

Cons- Security, service outage, storage limits, slow speeds, limited features and less control, provider time zones varying to that of end users causes convinience issues.

List the three types of testing data used in system development.

1. Normal Data

2. Boundary Data

3. Abnormal Data

What is Normal Data?

Data that is within the expected range and should be accepted by the system to ensure correct processing (e.g., entering 75 for a test score between 0 and 100).

What is Boundary Data?

Data that sits at the limits of the acceptable range. This is used to test if the system identifies the exact cut-off points correctly (e.g., entering 0 and 100 for a 0-100 range).

What is Abnormal Data?

Data that is outside the normal range or is of an unexpected type. This tests the system's ability to handle errors without crashing (e.g., entering "not a number" or -5 into a positive integer field).

Distinguish between Alpha Testing and Beta Testing.

• Alpha Testing: Conducted internally by the developers at the development site before the software is released. Typically done in lab environment. Focused on functional correctness, security aspects and software bugs

• Beta Testing: Conducted by limited group of end-users outside of organization in their own real-world environment to provide feedback on usability and bugs. Focused on unidentified bugs, usability and compatibility issues improving user experience

What is the purpose of User Documentation?

Explains how to use each part of a system, acts as a guide of systems features and characteristics. Poor or confusing documentations slows down implementations and increases support needs

List the three common methods of User Training.

1. Self-instruction

2. Formal classes

3. Remote/Online training

What are the advantages and disadvantages of Self-instruction?

Advantage: It is the lowest cost method and allows for a flexible schedule tailored to the user.

Disadvantage: It requires high user motivation and there is no expert available to help if the user becomes stuck.

What are the advantages and disadvantages of Formal classes?

Advantage: It provides a structured learning environment with direct access to an expert for immediate feedback.

Disadvantage: It can be expensive to organize and requires the user to be away from their desk at a specific time.

What are the advantages and disadvantages of Remote/Online training?

Advantage: It is highly scalable for large organizations and accessible from any location with an internet connection.

Disadvantage: It relies heavily on technical stability (e.g., internet speed) and lacks the personal touch of face-to-face instruction.

List the methods to prevent Data Loss.

1. Backups

2. Removable media

3. Offsite storage

4. Failover systems

5. Online storage

6. Antivirus and updates

7. UPS

8. Monitoring (SMART)

What is the difference between Backups and Offsite storage?

• Backups: Making regular copies of data to a secondary device to recover from local file corruption.

• Offsite storage: Storing those backups in a separate physical location to protect data against disasters like fire or theft at the main site.

What is a Failover system?

A redundant computer system that automatically takes over the functions of a primary system if it fails, ensuring system availability is maintained.

Contrast software Patches and Upgrades.

• Patches: Small updates designed to fix bugs or security vulnerabilities in existing software.

• Upgrades: Major releases that add new features and significant functional improvements to the system.

Local computing

Pros- Security, backups can be controlled, legacy software , software control, feature control

Cons- Cost of hardware, technical support, lack of collaboration

Pilot installation pros and cons

Pro- All features can be fully trailed, If new system dails only a small part of organisation suffers, staff who were part of pilot study can train other staff

Cons- For section that is piloting if system fails there is no backup

Common data migration problems faced

Incompatible file formats, data structure differences, validation rule issues and incomplete data transfer

Data structure differences and validation rule issues

Data migration problems that are regularly occuring

Data structure differences are how data is organized within a system. Without compatibility importing data to new system becomes harder

Validation rules ensure data accuracy and consistency.

Tips for successful data migration

Planning, data cleaning, testing and internationalization standards

Planning- analyze data formats and validation rules

Data cleaning- Ensure data is clean and complete

Testing- Identify any issues become full migration

Internationalization standards- Use international standards for data formats to minimise compatiblity problems

Gamma testing

Testing of software that is ready for release or close. Can happen when big changes occur after beta testing. Focuses on product readiness

Types of testing

Alpha

Beta

Gamma

Feedback collection

Iterative improvement

User acceptance testing (UAT)

Outline 3 main styles of user documentation

Tutorial- Step by step practical exercises, good for new users needing guided practice

Thematic- Chapter/section based and systematically covering each feature, Good for users learning system feature by feature

List/reference- Concise lists for quick lookup of commands, good for technical or experienced users needing fast answers

Methods of providing user documentation

Printed/PDF/ online manuals

Help files

FaQs

Live chat/video support

Pros and cons of Manuals and Help files in providing user documentation

Manuals:
Pros- Can be detailed, structured and printable. PDFs and web pages are easy to distribute

Cons- May become outdated, long manuals can be hard to search or intimidating

Help files:
Pros- Contextual help exactly where needed inside interface

Cons- May be brief or limited, not a full replacement

Pros and cons of FaQs and Live chat/video support in providing user documentation

FAQs:
Pros- Provide quick answers to common questions, accessible anytime.
Cons- May not cover all issues, can lack depth.

Live chat/video support:
Pros- Offers real-time assistance, personalized help for complex problems, human interaction.
Cons- May require waiting time, not always available.

Self instruction pros and cons

Pros- Users learn whenever needed through manuals, videos etc supporting just in time learning. Saves cost on instructors, venues and time away from work.

Cons- Success depends on user motivation and ability to learn independently, Lack of access or poorly designed training materials reduces effectiveness

Formal classes pros and cons

Pros- Real time interaction with instructor and peers, immediate feedback and questions, environment structured and focused on learning

Cons- Shy users may participate less, dominant personalities hinder inclusivity, instructor has limited time per individual

Common causes of data loss

• Accidental deletion- backups

• Computer viruses/malware

• Physical damage

• Continued use after warnings

• Power failure - use UPS

• Firmware corruption

• Natural disasters

Order of release strategies and what they are

1. Pre alpha- Very early internal build lacking features, only for developers

2. Alpha- Most main features added but quite buggy, tested within organisation

3. Beta- Feature complete and tested by external users

4. Release candidate- Almost ready for release, no new features only bug fixes

5. General availability- Stable public version for everyday use, later changes are patches/updates

Update strategies

• Automatic

• Manual

• Scheduled

• Phased/gradual rollout

Outline Pros and cons for automatic vs manual updates

Automatic:

Pros- Software installs updates itself making it effortless, updates improve security and compatibility

Cons- Needs internet, can install at bad times or c

Manual:

Pros- User controls which updates are installed and when, can avoid interruptions.

Cons- Forgetting or ignoring updates can miss improtant security or bug fixes, may not know how to update

Outline Pros and cons for scheduled vs phased updates

Scheduled:
Pros- Install at planned times reducing disruption

Cons- Delays urgent patches, if schedule fails users may be stuck on older versions for longer

Phased:
Pros- Limits impact of bad updates by testing on small groups, easier rollback if problems appear

Cons- Different users on diff versions at same time, hindering support and compatibility

Outline 3 reasons why updates matter

Important due to:

• Performance issues- Not updating can cause slower programs, higher cpu use, crashes and instability

• Security vulnerabilities- Regular updates patch known security gaps, reducing the risk of exploits and malware

• Compatibility- Updates ensure software works seamlessly with new features, operating systems, and hardware.

How to mitigate issues through change management?

Planning and communication- Clear explanations for changes, how they will be done and a timeline for implementation of new system keeping all involved informed reducing uncertainty

Training and support- Providing helpful resources like tutorials helps users adapt minimizing frustration and ensuring optimal use of new features

Risk management- Identify potential problems that may arise during change and developing stages to avoid them.

Factors to consider for successful change management

People- how change impacts diff user groups, address concerns and provide appropriate support

Technology- Ensure compatibility of existing infrastructure and data with new system through thorough testing

Processes- Update documentation and procedures to reflect changes made

Business mergers and compatibility and example

When business merge, existing computer systems need to be compatible in order to allow for transfer of data and smooth operating
Example- Two different companies may use similar but different ID fields or variables to store the core values meaning that reformatting would be required to merge the data.

International interactions and compatibility

When organizations collaborate internationally, issues from differences in the following can arise:
Software- one company might use software incompatible with the others systems

Languages- Software interfaces and data might be in different languages

Social and ethical considerations in compatiblity

Accessibility- if a new system isnt compatible iwth assistie tech, its not inclusive towards those with disabilities

Data privacy- Merging data from different systems raises user privacy and data protection concerns.