Software Development

Software Development Processes

A structured software development process was needed as software demands increased which meant that more people worked on developing software. This ensured that :

• User needs are met.
• Costs stayed within budget.
• Software was delivered on schedule.
• Cost of maintenance is minimised. There a several approaches to creating a software development structure.

Agile

Key Principles of Agile

• Engaging with customers and stakeholders throughout the development process for continuous feedback and alignment.
• Responding and embracing change even in the late stages of development to ensure the product meets the current needs.
• Prioritising delivering functional software over extensive documentation.

Waterfall Approach

Key Principles of the Waterfall Approach

• The project progresses in a strict sequence, with each phase dependent on the completion of the previous one.
• Extensive documentation is produced at each stage to ensure clarity and understanding of requirements, designs, and progress.
• Extensive documentation is produced at each stage to ensure clarity and understanding of requirements, designs, and progress.

Stages of Software Development

There are six stages in a standard software development process which combine features from an agile approach and a waterfall approach.

Investigation

Investigation involves analysing and identifying the nature of the problem that the software is expected to solve.

Types of Feasibility

• Technical feasibility : Assesses whether the technical resources and capabilities exist to complete the project.
• Economic feasibility : Determines whether the project is financially viable and cost-effective.
• Legal feasibility : Evaluates whether the project complies with all legal and regulatory requirements.
• Operational feasibility : Examines whether the organization has the capability to operate and support the project.
• Schedule feasibility : Assess whether the project can be completed within the desired time frame.
• Market feasibility : Determines whether there is a demand for the project's outcomes and if it will succeed in the market.

Planning

Planning involves defining the project scope, goals, resources, timelines and risk management strategies in order to set the foundations for a successful project.

Designing

The design stage involves translating requirements into a blueprint that developers can follow to build the software.

Top-Down Design

Modular Design

Prototyping

Key Characteristics of Prototypes

• It represents only the essential features and functionality needed to convey the concept.
• They are often interactive which allows users or stakeholders to utilise features early.
• They are usually developed in iterations allowing for multiple cycles of feedback.

Benefits of Prototypes

• Enhances Understanding : Helps clarify requirements and expectations, reducing misunderstandings.
• Early Feedback: Provides a basis for early user and stakeholder feedback, leading to better alignment with user needs.
• Improved Communication: Serves as a visual tool to improve communication among developers, stakeholders, and users.

User-Centered Design

7 Principles of Universal Design

1. Equitable Use

• The design is useful and marketable to people with diverse abilities.

2. Flexibility in Use

• Accommodates a wide range of individual preferences.

3. Simple & Intuitive Use

• Easy to understand, regardless of the user's experience, knowledge, language skills, or concentration level

4. Perceptible Information

• Communicates necessary information effectively to the user, regardless of ambient conditions or the user's sensory abilities.

5. Tolerance for Error

• Minimizes hazards and the adverse consequences of accidental or unintended actions.

6. Low Physical Effort

• Can be used efficiently and comfortably with minimum fatigue.

7. Size & Space for Approach & Use

• Provides appropriate size and space for approach, reach, manipulation, and use regardless of user's body size, posture, or mobility.

Creation

The creation stage is where the software is actually written

Evaluation

Testing

Testing software refers to the process of evaluating and verifying that a software application or system meets the specified requirements and works as expected.

Objectives of Testing

• Correctness : Ensures that the overall system still works even if a portion of the system has been altered, removed or added on.
• Verification : Ensures the software is built according to the specifications and design documents
• Fixing Bugs : Identifies defects in the software that could cause incorrect behavior or performance issues.

Types of Testing

Documentation

Documentation is a broad term in terms of software, it may include :

• Requirement documentation to describe functional and non-functional requirements of the software application.
• Design document to describe the architecture of the software.
• Technical document to provide detailed information about the code.
• User documentation on how to use the software such as tutorial and installation instructions.