Software Product Design vs Engineering

Software Design Principles and Practices

• Software design is crucial.
• It's best understood as problem-solving.
• Abstraction is a key technique in design.
• Modeling relies heavily on abstraction.
• Design involves both product and engineering aspects.
• Product design is primarily focused on requirements.
• Engineering design is concentrated during implementation and design phases.
• Object-oriented analysis and design techniques are becoming standard.

Objectives

• Describe design and how different types handle product aspects.
• Present design as problem-solving, emphasizing abstraction and modeling.
• Place design within the software life cycle.
• Examine software engineering design approaches.

Topics

• Software products and design
• Abstraction and modeling
• Design varieties
• Software design in the life cycle
• Software engineering design methods

Importance of Software Design

• Design is crucial in creating functional and useful products.
• Design significantly impacts our daily lives economically and in terms of quality of life.
• Software has become increasingly important and pervasive.
• High-quality design has significant effects.

Software Products

• A software product is a collection of programs, data, and supporting resources meeting user needs.
• It can exist as a standalone artifact or be a vital component of another system.

Software Design Defined

• Software designers apply principles used in other design fields to software.
• Software design is meticulously specifying software to satisfy user needs while adhering to limitations.

Design as Problem Solving

• Problem-solving forms the foundation of design.
• Design often involves multiple solutions.
• Approaches such as problem redefining, experimentation, and brainstorming are helpful in design.

Design Principles

• Design principles act as guidelines for building well-structured, maintainable, and efficient software systems.
• The principles make software easier to comprehend, adaptable and reusable.

Abstraction

• Essential for problem-solving, especially in complex software design.
• It's about selectively highlighting specific aspects of a problem and neglecting the rest to simplify.

Importance of Abstraction

• Simplifies problems to facilitate solutions.
• Aids in focusing on the core components of a problem.
• Two common approaches are "top-down" and "bottom-up" strategies.
• Top-down strategy starts with a general solution and refines it.
• Bottom-up strategy begins with details and combines them to create a whole.

Modeling

• Models showcase the target in a structured fashion.
• Model components correspond to system parts, and interactions among parts are well-defined.

Modeling in Design

• Models simplify problem understanding.
• They assist in design creation and investigation.
• Documentation is enhanced and facilitated by modeling.

Static and Dynamic Models

• Static models depict software aspects that remain unchanged during runtime.
• Dynamic models portray the software's behavior during execution.

Design Methods and Components

• Design methods are systematic approaches to creating precise and complete software solutions.
• They comprise: a process, symbolic representations, principles, and rules (heuristics) to solve specific design problems.

Design Practices

• They offer established approaches and guidelines used to develop effective, maintainable, and scalable software systems.
• Include SOLID principles, design patterns, and processes for abstraction, decomposition, encapsulation, documentation, etc.

Design Practices (Continued)

• SOLID principles provide a structured approach to object-oriented software design.
• Design patterns offer tested solutions to common design challenges.
• Architectural patterns delineate high-level components for structuring complex systems (e.g., MVC, microservices).

Design Practices (Continued)

• Abstraction simplifies complex systems to focus on details.
• Decomposition breaks down intricate parts into smaller, well-defined components (eg., modules, classes, services).
• Encapsulation combines data with operations to protect data integrity.
• Documentation communicates design decisions through visual aids.

Why Design Practices Matter

• Follows a definite structure helping software adapt to modifications.
• Leads to high-quality products.

Design Principles Importance

• Provide guidelines for cleaner, reliable, and more manageable code.
• Reduced errors, flexibility, and better access for maintainers.

Design Method Timeline

• Historical overview of design methodology evolution.

Summary

• Software design is important, focusing on problem-solving.
• Abstraction and modeling are foundational techniques.
• Effective design incorporates both product and engineering considerations.
• Development phases (requirements, design, implementation, testing, and maintenance) are well-defined.
• Object-oriented approaches are standard in modern software engineering.

Thank You