Summary of "Types of Software Maintenance (Corrective, Adaptive, Perfective, and Preventive)"

This video explains the concept of Software Maintenance, its importance, and the four main types of maintenance that software undergoes after its initial launch. The key points and lessons are outlined below:

What is Software Maintenance?

Software Maintenance involves modifying software after its release to meet evolving customer needs.
It includes adding, changing, updating, or removing features.
Maintenance is crucial for keeping software competitive, relevant, and functional over time.
Software development is ongoing, and maintenance ensures software longevity.

Importance of Software Maintenance

Cost Savings: Maintaining existing software is cheaper than developing new software from scratch.
Adapting to Technological Changes: Software must evolve with new technologies and market demands.
Enhancements: Updating software to meet new user requirements or external changes.
Preventing Failures: Proactively reducing or avoiding future system failures through monitoring and maintenance.

Four Types of Software Maintenance

Each type serves different purposes and may be applied individually or in combination throughout the software lifecycle.

1. Corrective Maintenance

Purpose: Fix errors, faults, or bugs in the software caused by design flaws, logic errors, or coding mistakes.
Process: Starts with identifying errors (often from user bug reports), followed by investigation, analysis, design, testing, and implementation.
Examples: Fixing authentication errors, correcting incorrect program outputs.
Methodology: A scaled-down Software Development Life Cycle is used; updates are tested in controlled environments before deployment.

2. Adaptive Maintenance

Purpose: Modify software to accommodate changes in the environment or organizational policies.
Reasons:
- Environmental changes: Adapting to new hardware, operating systems, cloud services, etc.
- Organizational changes: Adjusting to new procedures, goals, policies, security requirements, or information needs.
Effect: Ensures software continues to run smoothly and meets new external or internal demands.

3. Perfective Maintenance

Purpose: Improve software by adding new features or enhancing existing ones based on user feedback or evolving requirements.
Focus: Enhances functionality, reliability, efficiency, and usability, even when no faults exist.
Examples of internal changes: Switching from command line to GUI, upgrading wireless networks, adding voice-based search.
Examples of external changes: Adapting to new laws or policies (e.g., single currency adoption), responding to economic competition (e.g., e-commerce features), incorporating new technologies (e.g., Progressive Web Apps).

4. Preventive Maintenance

Purpose: Proactively prevent potential future issues and extend software lifespan by addressing latent faults.
Goals:
- Avoid future failures or faults.
- Prevent software deterioration.
- Maintain long-term software functionality.
- Reduce risks associated with extended operation.
Characteristics: Performed internally by maintenance teams without external requests.
Examples:
- Applying software updates to fix vulnerabilities.
- Keeping documentation current.
- Conducting security audits.
- Restructuring code to improve maintainability without changing behavior.

Conclusion

Software Maintenance is an ongoing, essential process to keep software effective, secure, and up-to-date.
Understanding the four types of maintenance helps in managing software through its lifecycle.
Proper maintenance strategies reduce costs, improve software quality, and extend system longevity.