WEEK 10-11: REQUIREMENTS MODELING

Requirements Modeling

• Is a process of of documenting, analyzing, and managing requirements.

• Known as the technique of modeling requirements and solutions as they change through collaborative work and cooperation.

Requirements Modeling 3 Main Activities

1. Analysis

2. Documentation

3. Management

Analysis

Collected requirements are evaluated for completeness, consistency, and clarity, addressing any ambiguities or inconsistencies.

Documentation

Requirements are clearly documented to ensure understanding and easy reference by all stakeholders.

Management

Requirements are actively managed throughout the project, including tracking changes, communicating updates, and ensuring ongoing alignment with project

Benefits of Requirements Modeling

Enhances the clarity of requirements, significantly impacting the success of software projects.

Key Advantages of Requirements Modeling

1. Creating simulations is a breeze

2. Automatic document generation

3. Automatics Test Conduction

4. Easy integration with development and testing tools

5. Easy requirements change management

• Is crucial for efficient software delivery. It helps clarify the project for both developers and clients, addressing concerns early and guiding development.

• This process reduces risks by ensuring that requirements are well understood and provides a clear plan for the project.

• Without it, projects risk delays, cost overruns, or failure. It also helps new team members quickly understand the project.

Why is Requirements Modeling Important?

Requirements Modeling Techniques

1. Requirements Traceability Matrix

2. Use Cases

3. User Stories

4. Process Flow Diagrams

5. Activity Diagram

6. State Diagram

7. Sequence Diagrams

Requirements Traceability Matrix

Is a table that shows the relationships between requirements. It can be used to ensure that all requirements are being met.

Use Cases

Describes how a user interacts with a system to achieve a specific goal, capturing functional requirements and outlining the system's key functionalities.

User Stories

Is a brief, straightforward description of a feature from the user's perspective, used to capture both functional and non-functional requirements.

Process Flow Diagrams

Illustrates how tasks are carried out in a process and can be used to capture both functional and non-functional requirements.

Activity Diagram

• This approach outlines the entire business or system process, making it suitable for various users based on functional and fundamental requirements.

• However, it only defines the system's scope and does not support detailed impact analysis.

State Diagram

• Provides a more detailed representation than a flow chart, illustrating the different states of an object within a process flow.

• However, it is not suitable for direct use in impact analysis calculations.

Sequence Diagrams

• This approach is particularly useful for technical users, as it visually represents the interactions between processes or objects during a scenario.

• It helps clarify specific technological specifications and is widely used for requirement references during the development phase due to its effectiveness.

Requirements Modeling Elements

1. Flow Oriented Modeling

2. Class-based Modeling

Flow Oriented Modeling

The data objects are transformed by the function as it is processed.

Flow Oriented Modeling Examples

1. Data Flow Model

2. Control Flow Model

3. Control Specification

4. Process Specification

Data Flow Model

It is a graphical technique. It is used to represent information flow.

Control Flow Model

Large class applications require control flow modeling.

Control Specification

The state diagram in the control specification is a sequential specification of the behavior.

Process Specification

The process specification is used to describe all flow model processes.

Class-based Modeling

Represents the object. The system manipulates the operations.

Class-based Modeling Examples

1. Classes

2. Attributes

3. Operations

Classes

To figure out which —— to take, underline each noun or noun clause in the text and enter it into the table.

Attributes

• Are the data objects that define a class within the context of the problem.

• For example, ’employee’ is a class consisting of the name, Id, department, designation, and salary of the employee.

Operations

Describe the actions of a thing.

Types of System Models

1. Context Model

2. Interaction Model

3. Structural Model

4. Behavioural Model

Context Model

• The external perspective model shows how a system interacts with its environment and other systems, defining the system's boundaries.

• It helps determine the system's functionality and how it relies on surrounding systems for support.

• The —— illustrates these interactions to ensure the system works well within its environment.

Interaction Model

The interaction perspective model explains how different parts of a system interact.

3 Types of Interactions

1. User interaction

2. System interaction

3. Component interaction

User interaction

How users provide input and receive output, helping identify user needs.

System interaction

How the system interacts with other systems, highlighting potential communication issues.

Component interaction

How internal system components interact, ensuring the system meets performance requirements.

2 Kinds of Diagrams

1. Use Case Diagram

2. Sequence Diagram

Structural Model

The structural perspective model shows how a system is organized, focusing on its components and their relationships.

1. Static Models

2. Dynamic Models

Structural Model includes?

Static Models

Represent the system's structure.

Dynamic Models

Show the system's organization during execution.

3 Types of Structural Model

1. Class diagrams

2. Generalizations

3. Aggregation

Class diagrams

Depict system classes and their relationships.

Generalizations

Shows inheritance relationships between classes.

Aggregation

Represents whole-part relationships within the system.

Behavioural Model

The behavioral perspective model represents the system's dynamic behavior.

2 Types of Behavioural Model

1. Data-driven modeling

2. Event-driven modeling

Data-driven modeling

Focuses on how data moves through the system.

Event-driven modeling

Focuses on how the system responds to events or changes.

Computer Aided Software Engineering (CASE)

• Refers to tools and methods that improve software development quality and efficiency.

• It facilitates a structured approach, helping teams track milestones and maintain project documentation.

• A key benefit is ensuring the final product meets real-world requirements by involving customers throughout the process.

• While CASE tools were once popular, interest has declined as they adapted to developer needs, and the concept has faced criticism since its introduction.

CASE Tools

• Are built-in programs designed to analyze and improve software systems, enhancing quality and outcomes.

• Gaining popularity in the 1990s, companies like IBM utilized these tools in software development.

• CASE encompasses various tools that support different stages and milestones within the software development life cycle.

Types of CASE Tools

1. Diagramming Tools

2. Computer Display and Report Generators

3. Analysis Tools

4. Central Repository

5. Documentation Generators

6. Code Generators

7. Tools for Requirement Management

8. Tools for Analysis and Design

9. Tools for Database Management

10. Tools for Documentation