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Chapter 1 The Systems Development
Environment
Modern Systems Analysis and Design
Seventh Edition
Jeffrey A. Hoffer Joey F. George
Joseph S. Valacich
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 2 Chapter 1
Introduction
n Information Systems Analysis and Design ¨ Complex organizational process ¨ Used to develop and maintain computer-
based information systems ¨ Used by a team of business and systems
professionals
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Introduction (Cont.)
3 Chapter 1
FIGURE 1-1 An organizational approach to systems analysis and design is driven by methodologies, techniques, and tools
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Introduction (Cont.)
n Application Software ¨ Computer software designed to support
organizational functions or processes n Systems Analyst
¨ Organizational role most responsible for analysis and design of information systems
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 5 Chapter 1
A Modern Approach to Systems Analysis and Design n 1950s: focus on efficient automation of
existing processes n 1960s: advent of procedural third
generation languages (3GL) faster and more reliable computers
n 1970s: system development becomes more like an engineering discipline
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 6 Chapter 1
A Modern Approach to Systems Analysis and Design (Cont.) n 1980s: major breakthrough with 4GL,
CASE tools, object-oriented methods n 1990s: focus on system integration, GUI
applications, client/server platforms, Internet
n The new century: Web application development, wireless PDAs and smart phones, component-based applications, application service providers (ASP)
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Developing Information Systems
n System Development Methodology is a standard process followed in an organization to conduct all the steps necessary to analyze, design, implement, and maintain information systems.
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Systems Development Life Cycle (SDLC) n Traditional methodology used to develop,
maintain, and replace information systems n Phases in SDLC:
¨ Planning ¨ Analysis ¨ Design ¨ Implementation ¨ Maintenance
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Standard and Evolutionary Views of SDLC
FIGURE 1-3 Evolutionary model FIGURE 1-2 Systems development life cycle
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Systems Development Life Cycle (SDLC) (Cont.) n Planning – an organization’s total
information system needs are identified, analyzed, prioritized, and arranged
n Analysis – system requirements are studied and structured
n Design – a description of the recommended solution is converted into logical and then physical system specifications
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 11 Chapter 1
Systems Development Life Cycle (SDLC) (Cont.) n Logical design – all functional features of
the system chosen for development in analysis are described independently of any computer platform
n Physical design – the logical specifications of the system from logical design are transformed into the technology-specific details from which all programming and system construction can be accomplished
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 12 Chapter 1
Systems Development Life Cycle (SDLC) (Cont.) n Implementation – the information system
is coded, tested, installed and supported in the organization
n Maintenance – an information system is systematically repaired and improved
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FIGURE 1-9 The heart of systems development
Chapter 1
The Heart of the Systems Development Process
Current practice combines analysis, design, and implementation into a single iterative and parallel process of activities.
FIGURE 1-8 Analysis–design–code–test loop
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Traditional Waterfall SDLC
One phase begins when another completes, with little backtracking and looping.
FIGURE 1-10 Traditional waterfall SDLC
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Problems with Waterfall Approach
n Feedback ignored, milestones lock in design specs even when conditions change
n Limited user involvement (only in requirements phase)
n Too much focus on milestone deadlines of SDLC phases to the detriment of sound development practices
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 17 Chapter 1
Different Approaches to Improving Development n CASE Tools n Rapid Application Development
(RAD) n Agile Methodologies n eXtreme Programming
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Computer-Aided Software Engineering (CASE) Tools n Diagramming tools enable graphical
representation. n Computer displays and report generators
help prototype how systems “look and feel”.
n IBM’s Rational products are the best known CASE tools.
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Computer-Aided Software Engineering (CASE) Tools (Cont.) n Analysis tools automatically check for
consistency in diagrams, forms, and reports.
n A central repository provides integrated storage of diagrams, reports, and project management specifications.
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 20 Chapter 1
Computer-Aided Software Engineering (CASE) Tools (Cont.) n Documentation generators standardize
technical and user documentation. n Code generators enable automatic
generation of programs and database code directly from design documents, diagrams, forms, and reports.
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 21 Chapter 1
CASE Tools (Cont.)
FIGURE 1-11 Screen shot of ArgoUML, an open source CASE tool (Source: http://argouml.tigris.org/)
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 23 Chapter 1
Rapid Application Development (RAD)
n Decreases design and implementation time
n Involves: extensive user involvement, prototyping, integrated CASE tools, code generators
n More focus on user interface and system function, less on detailed business analysis and system performance
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Rapid Application Development (RAD) (Cont.)
FIGURE 1-12 RAD life cycle
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Agile Methodologies
n Motivated by recognition of software development as fluid, unpredictable, and dynamic
n Three key principles ¨ Adaptive rather than predictive ¨ Emphasize people rather than roles ¨ Self-adaptive processes
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 26 Chapter 1
The Agile Methodologies group argues that software development methodologies adapted from engineering generally do not fit with real-world software development.
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall
When to use Agile Methodologies
n If your project involves: ¨ Unpredictable or dynamic requirements ¨ Responsible and motivated developers ¨ Customers who understand the process and
will get involved
27 Chapter 1
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eXtreme Programming
n Short, incremental development cycles n Automated tests n Two-person programming teams n Coding, testing, listening, designing
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eXtreme Programming (Cont.)
n Coding and testing operate together n Advantages:
¨ Communication between developers ¨ High level of productivity ¨ High-quality code
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Object-Oriented Analysis and Design (OOAD) n Based on objects rather than data or
processes n Object: a structure encapsulating
attributes and behaviors of a real-world entity
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Object-Oriented Analysis and Design (OOAD) (Cont.) n Object class: a logical grouping of
objects sharing the same attributes and behaviors
n Inheritance: hierarchical arrangement of classes enable subclasses to inherit properties of superclasses
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 33 Chapter 1
Rational Unified Process (RUP)
n An object-oriented systems development methodology
n Establishes four phase of development: inception, elaboration, construction, and transition ¨ Each phase is organized into a number of
separate iterations.
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 34 Chapter 1
FIGURE 1-13 Phases of OOSAD-based development
Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall 35 Chapter 1
Our Approach to Systems Development n The SDLC is an organizing and guiding
principle in this book. n We may construct artificial boundaries or
artificially separate activities and processes for learning purposes.
n Our intent is to help you understand all the pieces and how to assemble them.
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