1. What is Software Life Cycle?

Definition: The software life cycle (or software development life cycle, SDLC) is a structured sequence of phases involved in developing software, from initial concept to final deployment and maintenance.

Key Idea: Integrating HCI principles throughout the software life cycle ensures that user needs, usability, and interaction quality are addressed at every stage, not just after development.

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2. Phases of Software Life Cycle and HCI Role

1. Requirement Analysis / Feasibility Study

• Goal: Identify system requirements and constraints.

• HCI Role:

  • Conduct user research, interviews, and surveys
  • Identify user goals, tasks, and context of use
  • Define usability requirements along with functional requirements

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2. System Design / Conceptual Design

• Goal: Create the architecture and interaction framework of the system.

• HCI Role:

  • Develop interaction models and interface concepts
  • Create user personas, task models, and scenarios
  • Plan navigation structures, screen layouts, and information architecture

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3. Prototyping

• Goal: Build a preliminary version to visualize and test concepts.

• HCI Role:

  • Create low- or high-fidelity prototypes
  • Conduct usability testing to gather feedback
  • Refine interaction design, layout, and functionality iteratively

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4. Implementation / Development

• Goal: Convert designs into working software.

• HCI Role:

  • Ensure interface design is correctly implemented
  • Maintain consistency, accessibility, and usability standards
  • Developers and HCI specialists collaborate to ensure design fidelity

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5. Testing / Evaluation

• Goal: Verify that the system meets requirements and works correctly.

• HCI Role:

  • Conduct usability testing with target users
  • Identify interaction problems, errors, and inefficiencies
  • Assess user satisfaction, learnability, and performance

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6. Deployment / Installation

• Goal: Deliver the system to users for operational use.

• HCI Role:

  • Provide help systems, tutorials, and documentation
  • Ensure users can learn and adapt to the system effectively

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7. Maintenance / Evolution

• Goal: Update, improve, and fix the software post-deployment.

• HCI Role:

  • Collect user feedback and performance data
  • Refine interface, navigation, and interaction features
  • Adapt the system to changing user needs and technology

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3. Integration of HCI in Software Life Cycle

• Early involvement: Usability and user requirements should be considered from the beginning.
• Continuous evaluation: Iterative testing and feedback loops are crucial at every phase.
• Collaboration: Designers, developers, and stakeholders must work together to ensure user-centered outcomes.
• Documentation: Keep user requirements, design rationales, and usability reports throughout the SDLC.

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4. Benefits of HCI in Software Life Cycle

• Produces user-centered, usable software
• Reduces post-deployment errors and redesign costs
• Improves user satisfaction, efficiency, and adoption
• Supports continuous improvement through iterative feedback

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Key Takeaways

• HCI should be integrated into every phase of the software life cycle.
• Early and continuous user involvement prevents usability problems and reduces cost.
• Combining software engineering and HCI principles produces software that is both functional and user-friendly.