System Analysis and Design Lecture 4

System Analysis and Design

• A presentation on System Analysis and Design was given by Dr. Marwa Hussien Mohamed.
• The presentation was part of the Information Systems department, Faculty of Computer Science and Information Systems.

Lecture 4: Systems Development Methodologies

• Learning Objectives include describing various approaches to the System Development Life Cycle (SDLC) and explaining how to select a project methodology based on project characteristics.
• Systems development methodology is a formalized approach to implementing the SDLC. It's essentially a list of steps and deliverables.
• Many different methodologies exist, each varying in how progression through SDLC phases occurs.

Waterfall Development

• In waterfall development, analysts and users move sequentially from one phase to the next.
• Each phase is completed before the next begins.
• The approach is linear in structure.
• Advantages: Requirements are identified early and changes are limited. A structure is established.
• Disadvantages: Design must be complete before programming. A long time may elapse between proposal and system delivery. If requirements are incorrect, rework is costly.

Parallel Development

• Evolved to address the lengthy time frame of waterfall development.
• Projects are divided into subprojects that are designed and implemented in parallel.
• Subprojects are integrated after completion.
• Advantages: More efficient in reducing time to deliver a system, thus reducing rework due to changes in business.
• Disadvantages: Large volume deliverables. Difficult to integrate if subprojects are not completely independent.

Rapid Application Development (RAD)

• A collection of methodologies to improve on weaknesses of waterfall development.
• Incorporates special techniques and computer tools to speed up phases of analysis, design, and implementation.
• Goal is rapid development to user for evaluation.
• Advantages: System is developed faster and quality may be improved.
• Disadvantages: Can introduce problem in managing user expectations since users gain more understanding. This can accelerate changes to user expectations.

Iterative Development

• Projects are broken into series of versions.
• Fundamental requirements are in first version.
• First version is quickly developed (mini-waterfall), then users provide feedback for the next version.
• Advantages: Quickly delivers a preliminary system version to users. Additional needs can be incorporated into successive versions.
• Disadvantages: Users start with an incomplete system. Users need to be patient in the repeated introduction of new versions of the system.

System Prototyping

• Analysis, design, and implementation phases happen concurrently.
• Develops an initial, simplified system version (prototype).
• Initial prototype is often "quick and dirty" with minimal features.
• Feedback is used to improve subsequent prototypes.
• Refinement occurs until agreed-upon functionality is reached.
• Advantages: Useful when users have trouble expressing requirements, thus enabling exploration.
• Disadvantages: Potential lack of careful, methodical analysis prior to decision making. Limitations may result from inadequate understanding early in the project.

Throwaway Prototyping

• Several design prototypes are built during analysis and design phases.
• Prototypes are used to assess and validate potential issues in the system requirements.
• The prototypes are discarded after they have served their purpose.
• This distinguishes this method from system prototyping where prototypes evolve into the final product.
• Advantages: Ensures benefits of comprehensive analysis and design. Builds on advantages of prototypes in identifying issues. Produces a stable system.
• Disadvantages: Can take longer to produce final system compared to system prototyping.

Agile Development

• Streamlines SDLC, reducing modeling and documentation.
• Face-to-face communication is prioritized.
• Simple, iterative development approach. Every iteration is a complete software project.
• Iterations are short time-frames (one to four weeks).
• Emphasizing adapting to current business environment.

Extreme Programming (XP)

• Customer satisfaction, teamwork, communication, simplicity, and feedback are emphasized.
• Developers interact with customers. Designs are kept simple.
• Testing occurs early and frequently.
• Iterative development using user stories to describe system's needs. Modular code and testing to ensure fulfillment of needs.
• Quicker delivery than RAD approaches. Well-suited for smaller projects with motivated team and reliable business needs. Otherwise project success likelihood may be reduced.

Scrum

• Agile framework for complex projects.
• Iterative development.
• Emphasizes collaboration.
• Frequent communication ("Sprints").
• Specific phases include: Sprint Planning, Daily Scrum, Sprint Review, and Sprint Retrospective

Agile Principles

• Customer Satisfaction, Welcome Change, Deliver Frequently, Working Together, Motivated Team, Face-to-Face, Working Software, Constant Pace, Good design, Simplicity, Self-Organisation, Reflect and Adjust

How to Select a Development Methodology

• A table summarizes the usefulness of different methodologies in various conditions.. Provides a comparative table of usefulness in different systems development conditions. Includes considerations like unclear user requirements, unfamiliar technology, and complexity.

This quiz covers key concepts in System Analysis and Design, particularly focusing on Systems Development Methodologies. Participants will explore the System Development Life Cycle (SDLC) and evaluate different methodologies like Waterfall development. Understanding how to choose the right project methodology based on project characteristics is also emphasized.