System Life Cycle and Integration

System Life Cycle

• The system life cycle outlines the stages of developing a new system.
• Most systems start with analysis, then design and may return to earlier stages.
• Stages include: analysis, design, implementation, testing & debugging, software implementation, evaluation, deployment and maintenance.

Systems in Organizations

• New systems are created to replace inefficient, unsuitable, redundant, or outdated systems.
• The purpose is to improve productivity, quality and minimize costs.
• Computer systems include hardware, software, people, and the immediate environment.
• Planning a new system should anticipate organizational issues like lack of clear strategies, stakeholder participation, end-user support, and training.
• Feasibility studies evaluate project potential (technical, economic, legal, operational, and schedule).

System Integration Strategies

• Keeping existing systems and developing them for similar functionality (high maintenance cost)
• Replacing both systems with new ones (increased cost)
• Selecting the best system from each company and combining them
• Selecting one system and dropping the other

Types of Changeovers

• Parallel: Both old and new systems run simultaneously. This is the safest approach but costly.
• Big Bang/Direct (Immediate): The old system is stopped, and the new one is started immediately. This is fast but risky.
• Pilot: The new system is tested with a small group, then rolled out to the entire organization if successful. This is a risk-mitigation approach.
• Phased: The new system is introduced in stages. This is a more gradual approach, but takes longer to fully implement.

Data Migration

• Transferring data between different formats, storage types, and systems.
• This can be automated or manual.
• There are potential problems like incompatibility and data loss.

Types of Testing

• Functional testing: Testing individual commands and functions.
• Data testing: Testing with normal, abnormal, and extreme data.
• Alpha testing: Testing by the development company before the general public.
• Beta testing: Testing by users outside the development company.
• Dry-run testing: Testing involves pen and paper simulating the run.
• Unit testing: Testing individual components of a system.
• Integration testing: Testing the interactions between different components of a system.
• User acceptance testing: Testing by end-users to confirm the system meets their needs.
• Debugging: Systematic process of finding and fixing errors in a program.

User Documentation

• Manuals can be online or printed and the online option has multimedia capabilities.
• Email support allows users to contact support staff.
• Embedding assistance (context-specific help) enhances software usability.
• FAQs (Frequently Asked Questions) provide answers to common issues.
• Live chat support aids in resolving urgent issues quickly.
• Online portals provide access to updated manuals, support pages, and FAQs.
• Remote desktop connections allow a technician to control a user's PC remotely.

Methods of Delivering User Training

• Self-instruction/self-study: Users learn at their own pace using manuals, books, or online tutorials.
• Formal classes: Structured training with an instructor.
• Remote/online training: Allows participants to learn from anywhere through a computer and internet connection.

Data Loss Causes and Consequences

• Causes: Accidental deletion, administrative errors, poor data storage, data corruption, viruses, continued use after failure, firmware corruption, natural disasters, or physical damage.
• Consequences of data loss may vary.

Importance of User Documentation

• A crucial user aid that is easily accessible to describe how to use a program, system
• This is also critical for troubleshooting

Computer Hardware and Software

• Describes the physical components of a computer and the software (instructions for the CPU to work).
• Peripheral Devices are additional tools that work with the computer.
• Networks connect multiple computers together
• Special Roles within networks: dumb terminal, thin client, client, server, e-mail server, and domain name system server which attribute names to network addresses, and firewalls which control data flow between network entities

Subjects of Social and Ethical Significance

• Reliability: How well a system functions.
• Integrity: Ensuring data is complete and accurate.
• Inconsistency: Avoiding duplicate or outdated data
• Security: Protecting hardware, software, and networks from unauthorized access.
• Privacy: User control over the use and sharing of their data.
• Anonymity: Concealing identity in online activities.
• Intellectual property: Rights to original creations
• Digital divide and equality of access: Unequal distribution of information technology access
• Surveillance: Monitoring individuals or groups in digital spaces
• Globalization and cultural diversity: Impacts of IT on different cultures
• IT policies: Formal guidelines for IT use.
• Standards and protocols: Technical rules and conventions.

System Flowcharts (System Flowcharts or Data Flow Diagrams)

• Visual representations of data flow or processes within the system
• Show data paths (input and output)
• Structure charts describe the relationships between modules to support modular design approach