A1 Introduction to Systems Development_final

INTRODUCTION TO SYSTEMS DEVELOPMENT

  • Includes both methodology and artifacts employed during systems development.

INFORMATION SYSTEMS

  • Definition: Provide relevant data to users at all organizational levels.

  • Components:

    • Context: The environment in which the information system operates.

    • Data Collection: Relevant information and data regarding that context.

    • System Functions: Record, process, and regulate access to information.

COMPONENTS OF COMPUTER BASED INFORMATION SYSTEM

  • Information System Components:

    • Hardware: Physical devices necessary for the system.

    • Software: Applications and programs that process data.

    • Users: Individuals who interact with the system.

    • Documents: Information produced and processed by the system.

    • Procedures: Protocols and guidelines for using the system.

SYSTEM DEVELOPMENT PROCESSES

  • Various software development processes:

    • Traditional Systems Development Life Cycle (SDLC): The classic waterfall model.

    • Object-Oriented Model: Focuses on objects and their interactions.

WATERFALL MODEL

  • Features:

    • Each stage is discrete and focuses on specific project activities (e.g., problem definition, design).

    • Each completed stage results in a deliverable.

    • The model follows a linear sequence, resembling a waterfall, with no returning to previous stages.

STAGES OF WATERFALL MODEL

  1. Feasibility Analysis

  2. Design

  3. Implementation

  4. Testing

  5. Maintenance

SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) STAGES

  • Step-by-step process includes:

    1. Problem Definition

    2. Feasibility Study: Evaluates economic, technical, and organizational aspects.

    3. Requirements Analysis: Define "WHAT" the system should do.

    4. Design: Specify "HOW" the system will meet requirements.

    5. Implementation: Installing and configuring the system.

    6. Maintenance: Ongoing support and updates.

OBJECT-ORIENTED MODEL

  • Development process is iterative and includes:

    • Object-oriented analysis

    • Object-oriented design

    • Implementation: Occurs in small, repeated stages.

OBJECT-ORIENTED ANALYSIS

  • Activities:

    • Identify users.

    • Develop business models using activity diagrams.

    • Create various diagrams:

      • Use case diagrams

      • Interaction diagrams (e.g., sequence diagrams)

      • Class diagrams

      • State diagrams

    • Iterate and refine the models.

OBJECT-ORIENTED DESIGN

  • Application:

    • Design entity classes, attributes, methods, and associations.

    • Focus on data access and user interface classes.

    • Iterate and refine the design based on analysis feedback.

OBJECT-ORIENTED IMPLEMENTATION

  • Steps:

    • Code utilizing case tools or object-oriented programming languages.

    • Test for user satisfaction and quality assurance.

    • Deploy and iterate based on user feedback.

PROJECT ANALYSIS

  • User Requirement Gathering:

    • Stages:

      • Gather and validate requirements.

      • Record requirements and monitor implementation.

USER REQUIREMENT INTERVIEW

  • Key Components:

    • Use open-ended questions.

    • Identify stakeholders and understand their requests.

    • Conduct structured interviews.

EXAMPLES OF INTERVIEW QUESTIONS

  • What problem do you want the project/system to address?

  • Describe the key functions of the system needed.

  • What are the required levels of data and system security?

  • Discuss user group volumes, system availability, and necessary software/hardware.

  • Preferences for communication tools and user interface designs.

THREE MACRO PROCESSES

  • Identification:

    • Object-oriented analysis and design focus on refining models and usability.

    • The iterative process includes coding and testing for quality assurance and acceptance.

PROTOTYPING

  • Definition: An early version of software for testing and feedback.

  • Purpose: Helps understand user needs and usability of features.

RAPID APPLICATION DEVELOPMENT (RAD)

  • Overview: Development tools and techniques to create applications quickly.

  • Complements the SDLC, especially when combined with an object-oriented approach.

TYPES OF PROTOTYPES

  • Horizontal Prototype: Simulates user interface.

  • Vertical Prototype: Simulates functions.

  • Analysis Prototype: Focuses on problem simulation.

  • Domain Prototype: Evolves into the final product incrementally.

UNIFIED MODELLING LANGUAGE (UML)

  • Purpose: Visual modeling of systems with object-oriented approaches.

  • Origin: Resulted from the unification of major object-oriented methods.

  • Flexibility: Applicable across various programming languages and technologies.

UML DIAGRAMS

  • Types:

    • Use Case Diagram

    • Class Diagram

    • Object Diagram

    • State Diagram

    • Activity Diagram

    • Sequence Diagram

    • Collaboration Diagram

    • Component Diagram

    • Deployment Diagram

CLASSIFICATION OF UML DIAGRAMS

  • Static Diagrams: Represent structural aspects (e.g., Use Case, Class).

  • Dynamic Diagrams: Highlight behavioral aspects (e.g., Activity, State, Sequence).