Notes on the Process of System Development

INTRODUCTION

  • Information Systems Analysis and Design is essential for developing and maintaining computer-based information systems.
  • Driven by organizational needs (can be across entire enterprises or specific departments).
  • Critical for enhancing organizational processes and adding value to services/products.
  • Involves using a systems development methodology to structure the development of information systems.
  • The Systems Development Life Cycle (SDLC) is a common methodology that outlines the steps involved in system design and analysis.

OBJECTIVES

  • Define Information Systems Analysis and Design:
    • Understanding its role in improving organizational processes.
  • Describe the Information Systems Development Life Cycle (SDLC):
    • Familiarity with the phases that guide technology development.
  • Compare SDLC with alternatives:
    • Understand advantages and disadvantages for informed decision-making.

SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC)

  • The SDLC involves various phases that guide the design and analysis of systems. It's not strictly linear; phases can overlap or be revisited.
  • Different methodologies exist, but the typical framework is known as the “waterfall model”.
    • Phases overview:
    1. Project Identification and Selection
    2. Project Initiation and Planning
    3. Analysis
    4. Logical Design
    5. Physical Design
    6. Implementation
    7. Maintenance

PHASES OF SDLC

1. Project Identification and Selection

  • Identifying the need for new or improved systems.
  • Assessing organizational requirements and prioritizing needs.
  • Outcome: Determine which projects should be pursued.

2. Project Initiation and Planning

  • Investigating identified problems and defining project scope.
  • Developing a detailed plan that outlines project resources, timeline, and objectives.
  • Evaluating cost versus benefits to ensure project viability.

3. Analysis

  • Requirements determination is key, focusing on what users expect from the proposed system.
  • Involves careful examination of current systems and determining feasibility (technical, economic, operational, etc.).
    • Feasibility types include:
    • Technical Feasibility
    • Economic Feasibility
    • Behavioral Feasibility
    • Operational Feasibility
    • Legal Feasibility
    • Time Feasibility

4. Logical Design

  • Concentrates on system functionality independent of specific technological choices.
  • Ensures the system meets business needs without being tied to hardware/software.

5. Physical Design

  • Converts logical design into physical specifications for hardware and software.
  • Includes decisions about programming language, databases, and infrastructure.
  • Outputs the physical specifications needed for system builders.

6. Implementation

  • Turning the specifications into a working system through coding, testing, and installation.
  • Implementation involves three conversion types:
    • Direct Conversion: Immediate switch to the new system.
    • Parallel Conversion: Running old and new systems simultaneously until confidence in the new system is achieved.
    • Phased Conversion: Incrementally installing the system module by module.

7. Maintenance

  • Ongoing updates and refinements to adapt to user needs and changes in the environment.
  • Types include:
    • Corrective Maintenance: Addressing errors in the system.
    • Adaptive Maintenance: Modifying the system to meet new external conditions.
    • Perfective Maintenance: Enhancing system features to satisfy user requests.

PRODUCTS OF SDLC PHASES

  • Each SDLC phase has specific outputs:
    • Project Identification: Systems priorities and architecture outline.
    • Initiation and Planning: Work plan, scope definition, resource assignment.
    • Analysis: System need assessments and alternative justification.
    • Logical Design: Detailed specifications of system functions.
    • Physical Design: Technical specifications and acquisition plans.
    • Implementation: System code, documentation, and training materials.
    • Maintenance: Updated system versions and user support documentation.

APPROACHES TO DEVELOPMENT

1. Prototyping

  • A scaled-down version of the proposed system to refine user requirements through iterative feedback.
  • Allows for rapid development and user involvement.

2. Joint Application Design (JAD)

  • Involves users and developers in structured meetings to clarify requirements and design solutions.
  • Aims to create a shared understanding of the system's expected functionality.

3. Participatory Design (PD)

  • Encourages comprehensive user involvement in system development.
  • Users play a significant role in determining requirements and design decisions.

CASE STUDY: AUTOMATION OF LIBRARY SYSTEM

  • Current challenges: Manual transaction handling leads to inefficiencies.
  • Objectives of Automation: Provide a user-friendly interface, facilitate easy updates and manage book records efficiently.
  • Feasibility Concerns: Assessing technical, economic, and operational viability ensured that the project could be pursued.
  • Key Deliverables: Data dictionaries, user-friendly forms, effective input and output designs, and structured reports.

SUMMARY

  • Overview of the SDLC, its phases, and alternative approaches to improve systems development.
  • Emphasis on the iterative nature of SDLC in response to organizational changes and user feedback.