Chapter 1

Modern Systems Analysis and Design

• Modern Systems Analysis and Design is a complex process
• Information systems professionals develop and maintain information systems
• Application software supports organizational functions or processes
• Systems analysts are responsible for analyzing and designing information systems

Learning Objectives

• Define information systems analysis and design
• Describe the information systems development life cycle (SDLC)
• Describe agile methodologies, eXtreme Programming, and Scrum

Introduction

• Information Systems Analysis and Design: a complex, challenging, and iterative process used by teams to develop and maintain information systems
• Application Software: designed for organizational functions or processes
• Systems Analyst: organizational role responsible for information systems analysis and design

Figure 1-1: An Organizational Approach

• Systems analysis and design is driven by methodologies, techniques, and tools
• Methodologies provide a structured approach
• Techniques offer specific procedures
• Tools provide practical instruments

A Modern Approach to Systems Analysis and Design

• 1950s: Goal was efficiency in processing; automating existing processes; applications were built with machine or assembly language
• 1960s: Development of procedural languages; smaller, faster, and less expensive computers were enabled
• 1970s: System development became more organized and similar to engineering; shift from process-first to data-first
• 1980s: Major advancements like microcomputers as organizational tools; off-the-shelf software increased; 4th generation languages for instructing computers what to do instead of how to
• 1990s: System integration using visual programming, relational and object-oriented databases; enterprise-wide systems; web and internet applications emerged and expanded
• Present Day: Continued Internet and intranet systems; three-tier designs with separate databases, application, and client logic; wireless components; use of off-the-shelf components

Developing Information Systems and the Systems Development Life Cycle

• Systems development methodology: Standard process to analyze, design, implement, and maintain information systems
• Systems Development Life Cycle (SDLC): Traditional methodology for developing, maintaining, and replacing information systems; characterized by distinct phases for progression

Figure 1-2: Systems Development Life Cycle

• Circular process: the end of one project can lead to the start of another
• Iterative process: it's possible to return to prior phases
• Any given phase might require returning to prior phases if needed in the project's development

Figure 1-3: Evolutionary Model

• Spiral process: phases are constantly repeated at various points throughout the development, on increasingly detailed levels

Phases of the SDLC

• Planning: Identifying a need for a new system, analyzing needs and prioritizing them, defining scope, and creating a baseline project plan
• Analysis: Understanding system requirements from user input, studying current systems, and outlining alternate solutions
• Design: Converting alternate solutions into logical and physical specifications; logical design is independent of the specific platform; physical design includes technology-specific details and choices for programming language, database, and platform (often already decided by client/organization)
• Implementation: Coding, testing, and installing the system within the organization; allowing new systems to integrate within daily activities
• Maintenance: Repairing, improving, and updating the system over time to meet changing organizational needs

Table 1-1: Products of SDLC Phases

• Planning: prioritizes system development, creates an architectural design, outlines system management
• analysis: describes current systems, identifies alternative systems, explains why a chosen system was selected
• design: detailed specifications of data/processes/inputs/outputs of a system
• implementation: instructions/documentation/training for new or revised software
• maintenance: code modifications/documentation updates/training/support related to the software

Figure 1-6: Heart of Systems Development

• Activities and sequencing can vary among projects
• Analysis, design, and implementation frequently done as a single process

Figure 1-7: Traditional Waterfall SDLC

• Sequential phases; one phase completes before the next starts
• Changes are difficult and expensive later in the process; customers or users often have limited involvement because of the way the process works
• Role of users is often limited; focused on deadlines

Agile Methodologies

• Adapted from engineering, to fit real-world software development
• Three key principles: adaptive rather than predictive methodologies; a focus on people rather than roles; a focus on self-adaptive processes

Agile Methodologies (continued)

• Agile methodologies are not suited for every project
• Use agile when there is unpredictable/dynamic requirements; motivated developers; and customers who understand the process

Table 1-2: The Agile Manifesto

• Developed by seventeen anarchists
• Values: individuals/interaction, working software, customer collaboration, responding to change; less emphasis on detailed processes/tools or documentation
• Agile principles: customer satisfaction through continuous delivery of valuable software; welcome changing requirements; deliver software at short intervals, businesspeople and developers work together daily, build projects around motivated individuals, and effective communication with in-person interactions. Working software is the measure of progress.

Table 1-3: Five Critical Factors That Distinguish Agile and Traditional Methodologies

• Size: agile methods are better for smaller teams/products; traditional for large teams/products
• Criticality: agile methods for non safety-critical products; traditional methods for safety-critical products.
• Dynamism: agile adaptable to change; traditional methods are resistant to change and are best suited in stable environments
• Personnel: agile methods need sufficient technical knowledge, flexibility in roles and skill availability; traditional methods need particular expertise in project initiation
• Culture: agile promotes flexibility/collaboration; traditional methods emphasize rigid practices.

eXtreme Programming

• Short, incremental development cycles
• Automated tests written by programmers
• Two-person programming teams
• Customer involvement for monitoring the development process
• Unified approach of planning, analysis, design, and construction blended into a single phase
• Unique approach for capturing/presenting system requirements and specifications
• Related coding and testing
• Increased communication among developers, improved productivity, and higher-quality code

Scrum

• Methodology originated in 1995
• Most popular agile method (87% of companies report using it).
• Scrum framework includes teams with roles (product owner, development team, Scrum master), events (sprints, daily stand-ups, sprint reviews, sprint retrospectives), artifacts (product backlog, sprint backlog, increments)
• The Sprint cycle: two weeks-to-a-month; planning, daily standups, evaluation, and feedback
• Primary unit is the sprint; the teams evaluate progress during daily meetings and have meetings at the end to assess product goals and feedback on individual performance.

Agile in Practice

• Offers more choice in product development; but can be challenging for management
• Implementation requires top management support and knowledge throughout the organization
• Overcoming resistance to change is a key factor
• 42% of companies use combined agile/waterfall methods