Chapter 1 Assuming The Role Of The Systems Analyst
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Transcript Chapter 1 Assuming The Role Of The Systems Analyst
Chapter 1
Introduction to Systems
Design and Analysis
Systems Analysis and Design
Kendall and Kendall
Sixth Edition
Readings & Major Topics
Readings
Chapter 1 (p. 1) in the textbook
Major Topics
Information systems
SDLC (Systems Development Life Cycle)
Phases of analysis and design
CASE tools
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Information
What is information?
Domain dependent
Facts, concepts, or instructions; any sort of knowledge
or supposition which can be communicated.
Organizational resource
Must be managed as carefully as other resources (e.g.,
raw material, labor)
Costs are associated with information processing
Production, distribution, security, storage, retrieval, …
Information processing must be managed to take full
advantage of its potential
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Systems Analysis & Design
Goals
Analyze data input, processing or
transforming data, data storage, and
information output within the context of a
particular business
Analyze, design, and implement
improvements in the functioning of a
business via the use of computerized
information systems
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How can we Analyze and Design
Systems?
Intuitive approach
Pros and Cons?
Systematic approach
Pros and cons?
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Systems Analysis and Design in
this Course
Systematic approach to identifying
problems, opportunities, and objectives;
analyzing the information flows in
organizations; and designing
computerized information systems to
solve a problem
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Systems Analyst
Performs systems analysis and design
Assesses how businesses function by
examining the inputting and processing
of data and the outputting of
information with the intent of improving
organizational processes
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Different Types of Systems Analysts
Two major types
Outside consultants to businesses
Hired specifically to address information systems issues
within a business
Supporting experts (within a business you are regularly
employed)
Not a full-blown systems project, but rather entails a small
modification or decision affecting a single department
Your role as a systems analyst: agent of change
Catalyst for change (i.e., improvements to the business
that can be done via information systems)
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Interactions of a Systems Analyst
A systems analyst interacts with users
at different levels in the organization
User managers
Operations workers
Systems managers
Systems designers
Programmers
….
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Qualities of a Systems Analyst
Analysts are problem solvers.
Communication skills
Analysts must be ethical with users and customers
ACM’s (Association of Computing Machinery) code of
ethics
…
respect the privacy of others
Give comprehensive and thorough evaluations of
computer systems and their impacts, including
analysis of possible risks
…..
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Systems Development Life
Cycle (SDLC)
SDLC is a systematic approach to
solving business problems
It is divided into seven phases
Each phase has unique activities
A phase is never accomplished as a
separate phase
Several activities can occur simultaneously
Activities may be repeated
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Phase 1: Identifying problems,
opportunities, and objectives
Identifying
Problems: don’t want to address the wrong
problems
Opportunities: situations that can be improved
Objectives: how can the organization reach its
objectives via computerized IS
Personnel involved
Analyst
User managers
Systems managers
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Phase 2: Determining Information
Requirement
Understand how the business functions and have
complete information on the people, goals, data, and
procedures
Interview management, operations personnel
Gather systems/operating documents
Use questionnaires
Observe the system and personnel involved
Learn the details of the current system functions:
who (people involved), what (business activities),
where (environment in which the work takes place),
when (timing), how (procedures), and the why (why
is it done this way)
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Phase 2: Determining Information
Requirement (cont’d)
Personnel involved
Analyst
User managers
Operations workers
Systems managers
Information Analyst (phases 1 and 2)
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Phase 3: Analyzing Systems
Needs
Analyzing system needs
Create data flow diagrams
Document procedural logic for data flow diagram
processes
Complete the data dictionary
Analyze structured decisions
Make semistructured decisions (decisions taken
under risk)
Prepare and present the system proposal
Recommend the optimal solution to management
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Phase 3: Analyzing Systems
Needs (cont’d)
Analyst makes recommendations to
management
Management decide whether to continue
or not
Personnel involved
Analyst
User managers
Systems managers
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Phase 4: Designing the
Recommended System
Accomplish the logical design of the
information system
Design the user interface
Design output
Design input
Design files and/or database
Design control and backup procedures
Produce decision trees or tables
Produce program specifications
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Phase 4: Designing the
Recommended System (cont’d)
Personnel involved
Analyst
System designer
User managers
Operations workers
Systems managers
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Phase 5: Developing and
Documenting Software
Develop any original software that is needed
Design computer programs using structure
charts, Nassi-Schneiderman charts, and
pseudocode
Walkthrough program design
Write computer programs
Document software with help files, procedure
manuals, and Web sites with Frequently Asked
Questions (FAQs)
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Phase 5: Developing and
Documenting Software (cont’d)
Personnel involved
Analyst
System designer
Programmers
Systems managers
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Phase 6: Testing and Maintaining
the system
Testing and maintaining the system
Test and debug computer programs
Test the computer system
Enhance system
Personnel involved
Analyst
System designer
Programmers
Systems management
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System Maintenance
Maintenance: starts in phase 6 but
carried out routinely throughout the life
of the IS
System maintenance is
Removing undetected errors, and
Enhancing existing software
Time spent on maintenance typically
ranges from 48-60 percent of total time
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System Enhancements
Systems are enhanced for the following
reasons:
Adding additional features to the system
Business and governmental requirements
change over time
Technology, hardware, and software are
rapidly changing
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Phase 7: Implementing and
Evaluating the System
Implementing and evaluating the system
Plan conversion from the old system to the
new one
Train users
Purchase and install new equipment
Convert files
Install system
Review and evaluate system: whether the
intended users are indeed using the system
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Phase 7: Implementing and
Evaluating the System (cont’d)
Personnel involved
Analyst
System designer
Programmers
User managers
Operations workers
Systems managers
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CASE Tools
Computer-Aided Software Engineering (CASE)
CASE tools are automated, microcomputer-based
software packages for systems analysis and
design
Four reasons for using CASE tools are:
To increase analyst productivity
Facilitate communication among analysts and users
Providing continuity between life cycle phases
To assess the impact of maintenance
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CASE Tool Categories
CASE tools may be divided into several
categories
Upper CASE (also called front-end CASE)
tools, used to perform analysis and design
Lower CASE (also called back-end CASE).
These tools generate computer language
source code from CASE design
Integrated CASE, performing both upper
and lower CASE functions
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Upper CASE
Upper CASE tools
Create and modify the system design
Store data in a project repository
The repository is a collection of records,
elements, diagrams, screens, reports, and
other project information
These CASE tools model organizational
requirements and define system
boundaries
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Lower CASE
Lower CASE tools generate computer
source code from the CASE design
Source code may usually be generated
in several languages
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Lower CASE: Advantages of
Generating Code
Time to develop new systems decreases
The time to maintain generated code is less
than to maintain traditional systems
Computer programs may be generated in more
than one language
CASE design may be purchased from thirdparty vendors and tailored to organizational
needs
Generated code is free from program coding
errors
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Reverse Engineering
Reverse engineering is generating the
CASE design from computer program
code
Source code is examined, analyzed, and
converted into repository entities
Uses Computer-Assisted Reengineering
(CARE) software
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Reverse Engineering Produces
Depending on the tool set used:
Data structures and elements, describing
the files, records, and field
Screen designs, if the program is online
Report layouts for batch programs
A structure chart showing the hierarchy of
the modules in the program
Database design and relationships
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Advantages of Reverse
Engineering
It has the following advantages:
Reduced system maintenance time
Program documentation is produced for
loosely documented programs
Structured programs may be generated from
unstructured, older programs
Future system maintenance is easier to
implement
Unused portions of programs may be
eliminated
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