CS1004: Block 4 - Business Analysis

Waterfall model

A sequential, one-way, progressive flow of activity and information.

Advantages of the waterfall model

Practical and easy to use, simple structured approach, emphasis on analysis and design documentation.

Disadvantages of the waterfall model

Requirements, processes, and data structure evolve over time, technology and market changes rapidly.

When is the waterfall model appropriate

Systems not expected to change, safety-critical systems, computerizing existing manual systems without major changes.

RAD (Rapid Application Development)

Based on prototyping and incremental or evolutionary delivery.

Principles of RAD

Requirements not fully specified in advance, 80/20 rule, build most important requirements first.

DSDM

Evolved from RAD, focuses on quality assurance, more formalized procedures.

Extreme programming

Continuous development, testing, integration, frequent small releases, aims to improve software quality, productivity, responsiveness to changing requirements.

Characteristics of XP

Customer prioritizes work, pair programming, test-driven development, delay programming of features until needed.

Criticisms of Agile methods

Lack of design and documentation, need for above-average programmers, potential for "cowboy coding."

Differences between traditional vs. agile methods

Agile emphasizes continuous customer participation, timeboxing, iterative development, small teams.

System development participants

User/stakeholders, developer/programmer, analyst bridging communication gap.

Analyst

Communicates user requirements, translates them into computer programs, bridges developer-user gap.

Methodology

Collection of procedures, tools, aids developers in implementing Information Systems.

Levels of user engagement in Waterfall model

User agrees requirements, developers design and implement, user performs acceptance trials.

Levels of user engagement in RAD

User involved in critical decisions, "buys into" design decisions.

RAD Vs Waterfall (Cost, Time, Requirements)

Waterfall - Cost-flexible, Time-flexible, Requirements-fixed; RAD - Cost-fixed, Time-fixed, Requirements-flexible.

Four phases of RAD

Requirements planning, User design, Construction, Cutover.

Stages in System Development Life Cycle

Scope, Feasibility study, System Analysis, System Design, Implementation, System in use, Evaluation, Maintenance.

Cost of correction

Multiplied by 10.

Principles of DSDM

Empowered project team, user involvement, reversible changes.

Cowboy coding characteristic

Uncertain design requirements.