Chapter 8 - Systems Analysis and Design
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Transcript Chapter 8 - Systems Analysis and Design
Systems Analysis – ITEC 3155
Evaluating Alternatives for Requirements,
Environment, and Implementation
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Learning Objectives
Prioritize
the system requirements based on the
desired scope and level of automation for the
new system
Describe
the strategic decisions that integrate the
application deployment environment and the
design approach for the new system
Determine
alternative approaches for system
implementation
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Learning Objectives (continued)
Evaluate
and select an implementation approach
based on the needs and resources of the
organization
Describe
key elements of a request for proposal
(RFP) and evaluate vendors’ proposals for
outsourced alternatives
Develop
a professional presentation of findings to
management
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Overview
Chapter
explains last three activities of analysis
Prioritize systems requirements
Generate and evaluate alternatives
Review recommendation with management
Refocus
project direction
Transition
from discovery and analysis to
solutions and design
Set
direction for design and implementation of
solution system
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Project Management Perspective
Project
manager and senior technical members
of project team work together
Eight
areas of project management
Scope
Human resources
Time
Procurement
Cost
Communications
Quality
Risk
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Deciding on Scope and Level of Automation
(pg. 290)
Scope
determines which business functions will
be included in system
Level
of automation is how much computer
support exists for functions included in scope
Scope
creep
Requests for addition of system functions after
requirements have been defined and decision has
been made
Users
typically request more business functions
than budget allows
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Determining the Level of Automation
Low
level
Functions automated for simple computer record keeping
Medium
Midrange point that combines features from low and high
alternatives
High
level
level
System automates most processing of business functions
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RMO Customer Support System Functions, Priority, and
Three Levels of Automation (Partial Figure 8-1)
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Selecting Alternatives
Entire
group of alternatives is evaluated together
to provide “big picture” view of proposed system
Key
criteria that are used (pg. 294)
Strategic plan
Economic feasibility
Schedule and resource feasibility
Technological feasibility
Operational, organizational, and cultural feasibility
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Defining the Application
Deployment Environment
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(pg. 297)
Configuration
of
Computer hardware
System software
Networks
Development tools
Existing
environment generally considered and
compared with proposed environment
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Range of Application Types
Stand-alone
applications on mini- and personal
computers
Online
interactive applications
Distributed
applications
Web-based
applications
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Hardware, System Software, and
Networks
Computers
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range from handheld to super
computers
Operating
systems range from Windows to Unix
Database
management systems range from
Oracle to SQL Server to IBM DB2
Software
components and standards range from
Java 2 Enterprise (J2EE) to Microsoft .NET
Web
servers range from IIS to Apache
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Deployment Environment Characteristics
to Consider
Compatibility
with system requirements
Compatibility
among hardware and system
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software
Required
interfaces to external systems
Conformity
with IT strategic plan and architecture
plans
Cost
and schedule
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Development Tools
environment – programming
languages, CASE tools, and other software used
to develop application software
Development
Java
and Visual Studio .NET are examples
Application
deployment environment decisions
limit development tool choices
Operating system environment
Database management system (DBMS)
Distributed software standard
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Choosing Implementation Alternatives
(pg. 303)
Variations
on obtaining system
Facilities management – outsource all IS support
Packaged software, turnkey system, ERP system
Custom-built software systems
In-house development
Selection
dimensions
Buy vs. build
In-house vs. outsource
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Selecting an Implementation Alternative
Identifying
criteria for selection
Comparisons can be difficult
Different proposed systems have strengths in
different areas
Three
major areas to consider
General requirements
Technical requirements
Functional requirements
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Partial Matrix of Technical Requirements,
Weights, and Scores for Alternatives (Figure 8-9)
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Making the Selection
(pg. 310)
First,
rate each alternative with raw score
Weighted
scores are then tabulated and
compared to make a choice
RMO
decided on in-house development for most
CSS development to keep expertise within RMO
RMO
wants to hire some new technical
specialists
RMO
feasibility review showed no serious
problems – after specialists are added
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Contracting with Vendors
(pg. 311)
Generate
request for proposal (RFP)
Formal document sent to vendors if in-house
development is not selected
States requirements and solicits proposed
solutions
Considered a competitive contract offer
Bid on supplying hardware, software, and/or
support services
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Benchmarking and Choosing a Vendor
(pg. 312)
Observe
in use or install trial version
Benchmark
– evaluate the system against a
standard
Visit
another company using a particular system
Develop
a contract
Fixed-dollar – risk is on vendor
Cost-plus-percentage – risk is on purchaser
Cost-plus-fixed-fee – risk is shared by both
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Presenting Results and Making Decisions
(pg. 313)
Compile
and organize documentation
Present
alternatives and critical issues in easy-tounderstand but complete manner
Final
choice generally made by executive
steering committee
Format
of documentation and presentation style
varies with organization
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Summary
These
activities are primarily project manager
responsibilities with support from project team
Focus
of project changes from discovering
requirements to developing solution system
Prioritize
requirements based on scope and level
of automation
Scope of new system determines functions it will
support
Level of automation is a measure of how
automated the selected functions will be
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Summary (continued)
Application
deployment environment
Computer hardware, systems software, and
networks in which new system will operate
Determines constraints imposed on system
development alternatives
Analyst
must define environment to match
Application requirements
Organization’s strategic application plans
Organization’s technology architecture plans
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Summary (continued)
Determine
what alternatives are possible for
developing solution
Implementation
alternatives include
Building system in-house
Buying packaged or turnkey solution
Contracting with developer to build system
(outsource)
Develop
recommendations and present to
management to make funding decisions
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