Waterfall Model: Requirements Gathering

Waterfall Model: Requirements Gathering

Definition: Requirements gathering is the first phase of the waterfall model, where the project team collects and documents the customer's requirements.

Key Activities:

1. Elicitation: Gathering requirements through various means such as:
   • Interviews with stakeholders and customers
   • Surveys and questionnaires
   • Observation of existing systems and processes
   • Review of existing documentation and literature
2. Analysis: Examining and interpreting the gathered requirements to identify:
   • Functional and non-functional requirements
   • Constraints and assumptions
   • Ambiguities and inconsistencies
3. Documentation: Recording the requirements in a clear and concise manner, using:
   • Requirements specification documents (e.g., Business Requirements Document, Software Requirements Specification)
   • Use cases and user stories
   • Entity-relationship diagrams and data flow diagrams

Deliverables: The output of the requirements gathering phase is a comprehensive and unambiguous requirement specification document that serves as a basis for the rest of the project.

Key Characteristics:

• Freeze: Requirements are frozen after this phase, and changes are not allowed to ensure that the project scope is well-defined and stable.
• Completeness: The requirements gathering phase aims to collect all the necessary requirements to ensure that the project meets the customer's needs.
• Accuracy: The requirements must be accurate and unambiguous to avoid misunderstandings and misinterpretations.

Best Practices:

• Active involvement: Encourage active participation from stakeholders and customers to ensure that their needs are accurately captured.
• Clear communication: Ensure clear and concise communication to avoid misunderstandings and misinterpretations.
• Iterative refinement: Refine the requirements through iterations to ensure that they are accurate and complete.

Waterfall Model: Requirements Gathering

• Requirements gathering is the first phase of the waterfall model, where the project team collects and documents the customer's requirements.

Key Activities

• Elicitation involves gathering requirements through interviews, surveys, observation, and review of existing documentation and literature.
• Analysis examines and interprets gathered requirements to identify functional and non-functional requirements, constraints, assumptions, ambiguities, and inconsistencies.
• Documentation records requirements in a clear and concise manner using requirements specification documents, use cases, user stories, entity-relationship diagrams, and data flow diagrams.

Deliverables

• The output of the requirements gathering phase is a comprehensive and unambiguous requirement specification document that serves as a basis for the rest of the project.

Key Characteristics

• Requirements are frozen after this phase, and changes are not allowed to ensure that the project scope is well-defined and stable.
• The requirements gathering phase aims to collect all necessary requirements to ensure that the project meets the customer's needs.
• The requirements must be accurate and unambiguous to avoid misunderstandings and misinterpretations.

Best Practices

• Encourage active involvement from stakeholders and customers to ensure that their needs are accurately captured.
• Ensure clear and concise communication to avoid misunderstandings and misinterpretations.
• Refine the requirements through iterations to ensure that they are accurate and complete.

Software Engineering

• Software engineering is the process of analyzing user needs and designing, constructing, and testing end-user applications to satisfy these needs through software programming languages.
• It applies engineering principles to software development, focusing on larger and more complex software systems used as critical systems for businesses and organizations.

Software Systems vs. Hardware

• Large software systems can be more complex than the hardware used to run them, requiring best practices and engineering processes for development.
• Computer hardware becoming cheaper has shifted the focus to software systems, making software engineering crucial.

History of Software Paradigms

• The development of large software systems in the 1950s and 1960s led to the creation of Software Development Life Cycle (SDLC) models to govern the development process.
• Various process models have been developed over the years to guide software development activities.

Software Paradigms

• Software engineering paradigms, also known as software models or SDLC models, describe the tasks required for building high-quality software systems.
• The specific process model or paradigm used depends on the nature of the target system.
• Software paradigms provide a systematic approach, standard methodologies, and guidance to software engineers.

Software Development Life Cycle (SDLC)

• SDLC is the development strategy that encompasses the process, methods, and tools used in software development.
• It describes the period from conceptualization to discarding the software system after usage.
• Each paradigm has its own advantages and disadvantages, making some more suitable for developing specific software systems.

Software Process Tasks

• Common software process tasks, phases, and activities include:
  • Requirements Engineering: Software specification and functional requirements obtained from the user.
  • Requirements Analysis and Modeling
  • Architectural Engineering, implementation, and Design

Learn about the first phase of the waterfall model, where project teams collect and document customer requirements through various elicitation methods.