Strategic Usability Engineering Notes PDF

# Strategic Usability Engineering Notes ## Definition of Software Software refers to a collection of programs, data, and related documentation that instruct a computer on how to perform specific tasks. It includes: * **System Software:** Software that manages hardware and system resources (e.g.,...

# Strategic Usability Engineering Notes ## Definition of Software Software refers to a collection of programs, data, and related documentation that instruct a computer on how to perform specific tasks. It includes: * **System Software:** Software that manages hardware and system resources (e.g., operating systems, device drivers). * **Application Software:** Designed for end-users to perform specific tasks (e.g., word processors, web browsers). * **Middleware:** Acts as a bridge between system and application software to facilitate communication. * **Embedded Software:** Built into hardware devices, often with real-time constraints (e.g., firmware in medical devices, automotive control systems). ## Software Products Software products can be broadly classified into: 1. **Generic Software:** Developed for a broad audience with general-purpose functionality, often commercially available (e.g., Microsoft Office, Adobe Photoshop). 2. **Custom Software:** Tailored for specific clients or organizations to meet unique business requirements, built from scratch or adapted from existing solutions (e.g., enterprise resource planning systems, bespoke CRM solutions). ## Product Specification A software product specification (SRS) defines the functional and non-functional requirements, constraints, and design considerations for software development. It serves as a guideline for developers and stakeholders. The SRS document typically includes: * Functional requirements (features and functionalities expected) * Non-functional requirements (performance, security, usability, etc.) * System dependencies and constraints * Use case scenarios and workflows * Compliance and regulatory requirements ## Attributes of Good Software A high-quality software product should have the following attributes: 1. **Maintainability:** The ease with which software can be modified to correct defects, improve performance, or adapt to changes in the environment. 2. **Dependability & Security:** Ensuring software reliability, fault tolerance, and protection against cyber threats. 3. **Efficiency:** Optimal use of system resources like memory, CPU, and power. 4. **Acceptability:** Usability and user satisfaction, ensuring software meets user expectations and needs. 5. **Scalability:** Ability to handle increased loads and growing requirements. 6. **Interoperability:** Capability of the software to integrate and work with other systems. ## What is Software Engineering? Software engineering is the systematic application of engineering principles to software development, ensuring high-quality, scalable, and maintainable solutions. It involves structured methodologies for designing, developing, testing, and maintaining software products. ## Software Engineering Deals With: * Designing and developing software solutions. * Implementing software process models. * Managing project lifecycles effectively. * Ensuring software quality and usability. * Enhancing software security, maintainability, and adaptability. ## Software Process and Models A software process defines a structured set of activities required to develop software. Process models provide frameworks for executing these activities efficiently. ### Key Activities in Software Engineering 1. **Requirement Analysis:** Gathering and analyzing user and system requirements. 2. **System Design:** Architectural and component-level design of software. 3. **Implementation (Coding):** Writing and developing the software using programming languages. 4. **Testing & Validation:** Ensuring the software meets functional and non-functional requirements. 5. **Deployment:** Installing, configuring, and launching the software for users. 6. **Maintenance & Support:** Updating, patching, and enhancing software post-deployment. ## Software Process Models ### Waterfall Model A linear and sequential model with distinct phases: 1. **Requirement Analysis:** Documenting user and system needs. 2. **System Design:** Creating architectural and detailed designs. 3. **Implementation:** Writing the actual code based on the design. 4. **Testing:** Validating the software against requirements. 5. **Deployment:** Delivering the final product to users. 6. **Maintenance:** Updating and improving the software post-release. #### Issues with the Waterfall Model: * Late-stage defect detection can be costly. * Lack of flexibility; changes are difficult to accommodate. * Poor adaptability to evolving requirements. * Requires detailed planning and documentation before implementation. ### Incremental Model The software is built and delivered in increments, allowing partial implementation and improvements over time. #### Benefits: * Early delivery of functional software. * Easier to accommodate changes. * Reduced risk compared to the Waterfall model. * Continuous user feedback can be incorporated into iterations. #### Problems: * Requires careful planning and architecture. * Can be more expensive due to repeated cycles. * Managing multiple versions can be complex. ### Hierarchy: Process Models and Software Models Software development models (e.g., Waterfall, Agile) operate within broader software process frameworks to ensure structured development methodologies. Hierarchically, software process models define overall project execution, while software models focus on specific development methodologies. ## Why Use Standards? Standards provide a consistent, structured approach to software development, ensuring interoperability, quality, and compliance. ### Benefits of Standards * Improved software quality and reliability. * Easier collaboration and communication among teams. * Reduced risks and enhanced security through compliance. * Ensures best practices are followed industry-wide. * Facilitates regulatory compliance and legal adherence. ### Importance of Standards * Ensure software usability and accessibility. * Provide a common language for developers and stakeholders. * Facilitate compliance with industry regulations. * Enhance the efficiency of software design and development. ### Principles of Human-Centered Design 1. Understand the users and their needs. 2. Design for real-world tasks and user goals. 3. Create intuitive, user-friendly interfaces. 4. Evaluate usability iteratively through user feedback. 5. Ensure accessibility and inclusivity for all users. 6. Minimize cognitive load through effective design. ### Human-Centered Design Activities * User research and analysis - Understanding the target audience. * Conceptual and prototype design - Creating wireframes and mockups. * User testing and validation - Conducting usability testing sessions. * Iterative design improvements - Refining the product based on feedback. ## Conformance with Standards Ensuring compliance with usability and accessibility standards such as: * ISO 9241 - Guidelines on ergonomics of human-system interaction. * WCAG (Web Content Accessibility Guidelines) - Ensuring digital accessibility. * IEEE and ISO software engineering standards - Best practices for software development. ## Scrum Framework A popular Agile methodology focusing on iterative and incremental software development. ### Key Components of Scrum: * **Roles:** Product Owner, Scrum Master, Development Team. * **Artifacts:** Product Backlog, Sprint Backlog, Increment. * **Events:** Sprint Planning, Daily Stand-ups, Sprint Review, Sprint Retrospective. ### Benefits of Scrum: * Adaptability to changing requirements. * Increased collaboration and transparency. * Frequent delivery of working software. * Encourages continuous improvement and feedback. This document provides a structured and detailed approach to Strategic Usability Engineering, covering essential concepts, process models, usability principles, and industry standards.