Software Engineering Principles

• Software engineering ensures quality service in a user-friendly environment, abstracting complexity for ease of use.
• Building complex software involves intricate processes beyond just coding.
• A business analyst gathers business requirements, after which a development team creates a Software Requirement Specification (SRS).
• The process includes testing, acceptance, deployment, and maintenance, following the Software Development Life Cycle (SDLC).

Introduction to Software Engineering

• Software engineering combines software and engineering principles.
• Software is more than program code; it's executable code serving a computational purpose.
• Engineering involves developing products with well-defined scientific principles.
• A software product meets specific requirements.
• Software engineering develops software products using defined scientific methods, yielding efficient and reliable results.

Software Evolution

• Software evolution uses software engineering to develop a product, including initial development, maintenance, and updates, to meet requirements.
• Evolution starts with requirement gathering, followed by developers creating a prototype for user feedback early in development.
• Users suggest changes, leading to updates and maintenance, evolving the software.
• Changes are made to align existing software with the newest needs, instead of being recreated.

Software Paradigms

• Software paradigms are methods and steps for software design.
• These paradigms can be combined into categories, with each being contained in another.
• The programming paradigm is a subset of the software design paradigm, which is a subset of the software development paradigm.

Software Development Paradigm

• This involves applying engineering concepts to software development, including research and requirement gathering.
• Requirement gathering, software design, and programming are included in this paradigm.

Software Design Paradigm

• A part of software development includes design, maintenance, and programming.

Programming Paradigm

• This paradigm relates closely to the programming aspect of software development.
• Coding, testing, and integration are included in this paradigm.

Need for Software Engineering

• Software engineering is needed because of changing user needs and environments.
• It applies a scientific process to large software development.
• Without scientific concepts, recreating software would be easier than scaling existing software.
• Proper processes maintains the cost, despite lowering computer and electronic hardware prices.
• Software engineering facilitates enhancements necessary to adapt software to changing user environments.
• A better process provides a better and quality software product.

Characteristics of Good Software

• Judged by its offerings and usability, good software must be operational, transitional, and maintainable.
• Well-engineered has many characteristics, including effectiveness and efficiency

Operational Aspects

• Measures how well software functions, including areas of budget, usability, efficiency, correctness, functionality, dependability, security, and safety.

Transitional Aspects

• Important when software is moved across platforms, measuring portability, interoperability, reusability, and adaptability.

Maintenance Aspects

• Capabilities to maintain itself in a changing environment, looking at modifiability, maintainability, flexibility, and scalability
• Software engineering uses defined concepts to produce efficient, durable, scalable, on-time, in budget software.

Software Development Life Cycle

• Software Development Life Cycle (SDLC) provides well-defined and structured stages for software development.

SDLC Activities

• Provides a series of steps to design and develop software efficiently.
• Communication begins when a user requests a software product, negotiates terms with a service provider, and submits a written request.

Requirement Gathering

• The software development team works to understand the project and gathers information from stakeholders to define requirements.
• Requirements are classified into user, system, and functional, collected through studying systems, conducting interviews, and referring to databases or questionnaires.

Feasibility Study

• The team assesses whether the software can meet user needs and if the project is viable.
• It involves evaluating if the organization can undertake the project financially, practically, and technologically.

System Analysis

• Developers create a roadmap and choose a suitable software model, understanding product limitations and impacts.
• Assessing the project's scope and planning resources in advanced.

Software Design

• Requirements and analysis are used to design the software, creating logical and physical designs.
• Engineers produce metadata, data dictionaries, and diagrams.

Coding

• Also known as the programming phase, error-free executable programs make the software design implementation efficient.

Testing

• 50% of the development is for testing, ensuring critical level errors are removed.
• The process includes module, program, and product testing, with early discovery of errors being vital for reliable software.

Integration

• Integration happens by incorportating outer world entities
• This Involves libraries, databases, and/or software

Implementation

• Software is installed on user machines, with post-installation configurations and testing to solve portability, adaptability, and integration of related issues.

Operation and Maintenance

• The phase confirms the more efficient operation of the software with less errors.
• Training & documentation is used on how to keep it operational.
• Code updates and is maintained per ever changing user environment.

Disposition

• This involves archiving data and software components, closing down the system, planning closing activity and terminate timing.

Software Development Paradigm

• This helps developers choose a strategy and determine SDLC for software development.

Waterfall Model

• The Waterfall model means all SDLC will operate in a linear manner.
• The model assumes everything is perfectly planned and has no need to think about past mistakes that may arise.
• This model benefits developers that have designed already similar software and domain.

Iterative Model

• Software process projects are developed in repeating cycles after each step.
• The small scale is developed 1st and all those steps are considered.
• Afterwards more and more features are put into the software.

Spiral Model

• A combination of both iterative and SDLC projects.

V - Model

• Provides means of testing software at each stage in reverse.
• Test plans and test cases verify the validity of product according standard requirements.
• Validity of software is made visible at this stage.

Big Bang Model

• Little planning while using lots of programming and funds and it being based off the big bang of the universe.
• This results in the best software product and very little planning is needed.
• Not following the needs results in customer uncertainty and is arbitrary.
• Its a good method for experimenting and learning but large models should not do it.

Summary

• The point of Software engineering is not a new practice but a new basis as the need for software products grows.
• Ensures it all runs properly.
• In addition, less money and loss of reputation and even loss of life could be a result.