OOAD Unit-2: Inception Phase

Inception in OOAD

• Inception is the first phase of Object-Oriented Analysis and Design (OOAD) methodology, which involves gathering information and understanding the requirements for a new software project.
• The main objective of inception is to establish the scope of the project, identify the stakeholders, and define the initial set of requirements.
• Inception phase involves several activities, such as:
  • Identifying the problem
  • Defining the scope
  • Identifying stakeholders
  • Establishing project goals and objectives
  • Creating the initial requirements

Artifacts in Inception

• Artifacts in inception are the outputs of the inception phase.
• The common inception artifacts are:
  • Vision and Business Case
  • Use-Case Model
  • Supplementary Specification
  • Glossary
  • Risk List and Risk Management Plan
  • Prototypes and proof-of-concepts
  • Iteration Plan
  • Phase Plan and Software Development Plan
  • Development Case

Requirements

• Requirements are the high-level descriptions about a particular system, services, constraints, or to a detailed specification that are generated during the requirements gathering process.
• Requirements are capabilities and conditions needed by a user to solve a problem or achieve an objective.
• Types of requirements:
  • Functional Requirements
  • Non-Functional Requirements
• Categories of requirements:
  • User Requirements
  • System Requirements
  • Design Requirements
  • Domain Requirements

Use Cases and Use Case Model

• Use cases are a technique used to capture functional requirements of a software system.
• A use case represents a sequence of actions that the system performs in response to an external event to achieve a specific goal or objective.
• A use case typically consists of four elements:
  • Actors
  • Use Case Name
  • Description
  • Preconditions and Postconditions
• Use Case Model:
  • The Use-case model is defined as a model that shows how users interact with the system to solve a problem.
  • The use case model defines the user's objective, the interactions between the system and the user, and the system's behavior required to meet these objectives.

Use Case Diagram

• Use Case diagrams are one of the five diagrams in the UML for modeling the dynamic aspects of systems.
• The UML provides the use case diagram to illustrate the names of use cases and actors, and the relationships between them.
• Use case diagram components:
  • Actors
  • System
  • Goals
  • Use cases
  • Associations
• Use case diagram symbols and notation:
  • Use cases: Horizontally shaped ovals
  • Actors: Stick figures
  • Associations: A line between actors and use cases
  • System boundary boxes: A box that sets a system scope to use cases
  • Packages: A UML shape that allows you to put different elements into groups

Activity Diagram

• An activity diagram visually presents a series of actions or flow of control in a system similar to a flowchart or a data flow diagram.
• Activity diagrams are often used in business process modeling.
• Activity diagram symbols:
  • Activity nodes: Rounded rectangles
  • Control (Activity) flow arrows: Connect the activity nodes
  • Decision nodes: Diamonds
  • Merge nodes: Diamonds
  • Swimlanes: Organize activities and show the different actors or organizations involved in the process
  • Synchronization: Fork node and join node
  • Flow final nodes: Circle with a cross inside
  • Object nodes: Rectangles

Explore the concept of Inception in Object-Oriented Analysis and Design (OOAD) including artifacts and the initial steps involved in establishing the common vision and basic scope for a software project. Understand the importance of gathering information and defining requirements during the inception phase.