System Integration: Requirements Elicitation

• Requirements are an essential facet of system integration and architecture.

Requirements Elicitation

• Requirements elicitation identifies, gathers, and understands stakeholder needs and expectations for a software project.
• It is a critical phase in the Software Development Life Cycle (SDLC).
• It lays the foundation for defining the system's functionality, constraints, and objectives.

Stakeholder Identification

• Stakeholder Identification involves determining key users, clients, and decision-makers.

Techniques for Gathering Requirements:

• Interviews involve direct interaction with stakeholders to deep dive into their needs.
• Surveys gather quantitative data from a larger audience, providing a broader perspective.
• User Stories and Use Cases are narrative tools to visualize the end-user's interaction with the system.
• User stories describing how a customer uses an online shopping platform help developers understand necessary features.
• Prototyping creates mock-ups for validation.
• Clickable prototypes of a mobile app interface help stakeholders visualize the end product and suggest changes early in development.
• Requirement Workshops are collaborative sessions that bring stakeholders together to discuss and reconcile different needs and viewpoints.
• Conducting workshops with end-users, developers, and QA teams defines acceptance criteria for a new feature.
• Observation & Job Shadowing analyze existing workflows.
• Shadowing a nurse during their shift helps understand the requirements for a healthcare management system.
• Document Analysis reviews existing documentation to provide insights into current processes and systems, helping to identify areas for improvement.
• Analyzing user manuals helps identify gaps in current software functionalities.
• Brainstorming Sessions are collaborative sessions to explore ideas.
• A brainstorming session leads to the idea of integrating AI.

Requirement Classification

• Requirement classification involves Functional vs. Non-functional Requirements.

Functional Requirements (FR)

• Functional requirements define the specific features, functionalities, and behaviors the system must perform encompassing:
• User authentication and authorization.
• Data input and validation.
• CRUD operations (Create, Read, Update, Delete).
• Payment processing in an e-commerce system.
• Generating reports and dashboards.
• Key documents include Use Cases, User Stories, and Process Flows.

Non-Functional Requirements (NFR)

• Non-functional requirements define the quality attributes, constraints, and system performance that do not directly relate to specific functionalities.
• Types of NFRs
• Performance Requirements refer to system response time, load, and capacity metrics.
• Scalability is the ability to handle growing user loads.
• Security Requirements encompass data encryption, authentication, and standards.
• Usability Requirements specify the user experience and accessibility.
• Reliability & Availability ensure system uptime and error handling.
• Maintainability & Portability provide ease of updates.

How to Gather Functional and Non-functional Requirements

• Gathering requirements involves multiple approaches and collaboration between the development team, stakeholders, and end-users.
• Functional Requirements are gathered through interviews with stakeholders/users and surveys and workshops to brainstorm features and gather feedback.
• Non-functional Requirements gathering utilizes:
• Performance Benchmarks involving consultation with IT teams
• Security Standards defined with security experts
• Usability Testing to refine the interface

2. Requirements Documentation

• Software Requirements Specification (SRS) lists all requirements consistently.
• User Stories and Use Case Diagrams capture user needs and system interactions.
• Business Requirement Document (BRD) vs. Functional Requirement Document (FRD).

3. Requirements Maintenance & Management

• Change Management in Requirements.
• Version Control for Requirements.
• Impact Analysis of Requirement Changes.
• Handling Requirement Conflicts.

4. Modeling Tools and Methodologies Using UML

• UML Diagrams (Use Case, Class, Sequence, Activity, State Machine).
• Data Flow Diagrams (DFD).
• Entity-Relationship Diagrams (ERD).
• Business Process Model and Notation (BPMN).
• Agile Requirement Modeling (User Stories, Epics).

5. Testing of Requirements

• Requirements Validation and Verification.
• Test-Driven Development (TDD) and Behavior-Driven Development (BDD).
• Requirement-based Test Case Design.
• Ensuring Test Coverage of Requirements.
• Acceptance Criteria and User Acceptance Testing (UAT).

Sample User Stories for an Online Library Management System

• User Story 1 (User Registration):
• As a new user, I want to register with my email and password to access my account and borrow books.
• Acceptance Criteria: System should allow users to register with a valid email and password.
• User Story 2 (Borrowing a Book):
• As a registered user, I want to search for a book and borrow it so that I can read it within the allowed time.
• Acceptance Criteria:
• Users can search for books by title, author, or category.
• The system should check book availability.
• Users receive a due date for returning books.
• User Story 3 (Managing Books - Librarian Role):
  • As a librarian, I want to add, update, or remove books from the system to keep the library's book catalog up to date.
  • Acceptance Criteria:
  • Librarians can add book details title, author, ISBN, etc..
  • Books have a status(available, borrowed

Sample Use Case Diagram

• A visual representation of the system interactions.
• Actors: User Borrower & Librarian Admin
• Use Cases:
• Register/Login
• Search for Books
• Borrow Books
• Return Books
• Add/Update/Delete Books Librarian only
• Processes and Functionalities are actions/operations performed in the system, like user registration and book search.
• Modules are structural divisions grouping related functionalities like user and book management modules.
• Use Cases describe user interactions with specific functionalities
• Tools for visual use case diagram:
• Lucidchart
• Draw.io
• Microsoft Visio
• Gliffy
• Cacoo
• SmartDraw

Suggested Activities

• Prototype of the System Architecture using Visualization Software Figma, Adobe XD, Axure RP etc..
• Creating User Stories for Your Proposed System:
• Develop structured user stories. Instructions:
• IIdentify key usersstudents, customer, manager.
• Write user stories using the format: As a user, I want to, so that reason.
• Creating a Survey Questionnaire for the Proposed Information System.
• Designing an Entity-Relationship Diagram for a Database of your Proposed System.