Module title: Systems Analysis Fundamentals

What is Information Systems Analysis and Design?

What is Information Systems Analysis and Design? (continued)

Systems Analysis and Design: Core Concepts

Systems Analysis and Design: Core Concepts (continued)

A Modern Approach to Systems Analysis and Design

Developing Information Systems and the Systems Development Life Cycle

Developing Information Systems and the Systems Development Life Cycle (continued)

Phases of the Systems Development Life Cycle

Phases of the Systems Development Life Cycle (continued)

Alternative Approaches to Development (continued)

1.55M

valacichch01-3190923

1.

• Dr. Sinead O’Neill
• Email : sinead.oneill@wit.ie
• Contact time: College times – 9-5pm.
• Office : F21
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3. 4. Module title: Systems Analysis Fundamentals

1.1
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5. Module Descriptor

• Introduced to the main topics of Systems Analysis,
Design and Testing.
• Systems must be planned in order that all interested
parties can review and understand the necessary
system objectives.
• This module will introduce the student to the problems
associated with the development of systems;
• Methodologies, techniques and tools that are applied
to overcome some of these problems.
• During this module the student will be exposed to
techniques and tools applied within each phase of
system development.
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6. Indicative Content

• The Development Process
• Roles involved in the development process
• Planning & Requirements
• Analysis & Design
• Testing
• Implementation
• Post Implementation

7. Learning Outcomes

On successful completion of this module, a student will be
able to:
Identify systems development stages and the roles of the personnel involved.
Describe the requirements for the proposed system.
Identify the feasibility of the proposed system.
Model the proposed system requirements.
Identify appropriate testing techniques for a system.
Define the steps involved in migrating to the proposed system.
Describe all areas of maintenance/user support functions.
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8. Core Text

Essentials of Systems Analysis and Design
Fifth/Sixth Edition
Joseph S. Valacich
Joey F. George
Jeffrey A. Hoffer
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9. Assessment Methods

• 50% - final assessment (written exam)
• 50% - continuous assessment
• Group project 30%
• Written exam 20%
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10. Chapter Preview

• Systems Analysis is a proven method to help a
business utilize information to its fullest
capacity
• Systems Development Life Cycle (SDLC)
– Central to Information Systems Development
1.5
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11. 12. What is Information Systems Analysis and Design?

• A method used by companies to create and
maintain systems that perform basic business
functions
• Main goal is to improve employee efficiency
by applying software solutions to key business
tasks
• A structured approach must be used in order
to ensure success
1.6
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13. What is Information Systems Analysis and Design? (continued)

• Systems Analysts perform analysis and design
based upon:
– Understanding of organization’s objectives,
structure and processes
– Knowledge of how to exploit information
technology for advantage
• Fig 1-1 illustrates the Systems Development
Life Cycle, a four-phased approach used
throughout this text
1.7
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14.

1.14
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15. Information Systems in History

• IS have existed in some form throughout
history:
– Ancient Mesopotamian records of grain in city
storehouses (3500 BCE)
– Roman Empire records of property and tax
– 19th Century railway signalling systems
– The RAF’s communication and control system
used during the Battle of Britain(1940)
15
© 2010 Bennett, McRobb and Farmer

16. The Emergence of Modern IS

• Most IS today depend on digital electronic
computers
• Earliest examples (in Second World War)
include code-breaking Colossus Computer
• First business computer, Leo 1, built in 1951,
used for routine transactions like payroll and
managing inventory
• Modern IS used for vast range of purposes
16
© 2010 Bennett, McRobb and Farmer

17. The Role of the Computer

• Computers carry out tasks also done by
people and by other technologies
– Storage: signalman’s memory / hard disk
– Display: Battle of Britain map / PC screen
– Calculation: abacus / software program
– Communication: telephone line / LAN
• Typical advantages of computers:
– high speed, low cost, reliability
17
© 2010 Bennett, McRobb and Farmer

18. IS are Systems

18
© 2010 Bennett, McRobb and Farmer

19. Characteristics of Systems

• Every system has:
– Inputs and outputs
– A purpose (related to transformation)
– A boundary and an environment
– Subsystems and interfaces
– Control using feedback and feed-forward
– Some emergent property
19
© 2010 Bennett, McRobb and Farmer

20. Elements of an IS

• Every IS must have:
– A human activity that needs information
– Some stored data
– An input method for entering data
– Some process that turns the data into information
– An output method for representing information
• May also have:
– Subsystems that we can also regard as systems
– Interfaces with other systems
20
© 2010 Bennett, McRobb and Farmer

21. System Transformation

• All useful systems transform
– inputs => outputs
• inputs are - data or information and
• outputs -information
• This transformation is the whole reason for
building and operating the system
• It must render the input data useful in some
new way
21
© 2010 Bennett, McRobb and Farmer

22. Types of IS

• Information Systems are used to support
people’s activities
– Store and retrieve information
– Carry out calculations
– Aid communication
– Control and schedule work
– Other support …. ?
22
© 2010 Bennett, McRobb and Farmer

23. Systems Analysis and Design: Core Concepts

• Major goal:
– to improve organizational systems by developing
or acquiring application software and training
employees in its use
• Application software, or a system,
– supports organizational functions or processes
1.23
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24. Systems Analysis and Design: Core Concepts (continued)

• System: Turns data into information and includes:
– Hardware and system software
– Documentation and training materials
– Job roles associated with the system
– Controls to prevent theft or fraud
– The people who use the software to perform their jobs
• Figure 1.2 illustrates all the components of a system
1.24
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25.

26. Software Engineering Process

• A process used to create an information system
• Consists of:
– Methodologies
• A sequence of step-by-step approaches that help develop the
information system
– Techniques
• Processes that the analyst follows to ensure thorough, complete,
and comprehensive analysis and design
– Tools
• Computer programs that aid in applying techniques
1.26
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27.

28. Information System

• A system is an interrelated set of business
procedures used within one business unit
working together for a purpose
• A system has nine characteristics
• A system exists within an environment
• A boundary separates a system from its
environment
1.28
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29.

30. Characteristics of a System

31. Important System Concepts

• Decomposition
– The process of breaking down a system into smaller
components
– Allows the systems analyst to:
• Break a system into small, manageable and understandable
subsystems
• Focus on one area at a time, without interference from other
areas
• Concentrate on component pertinent to one group of users
without confusing users with unnecessary details
• Build different components at independent times and have
the help of different analysts
1.31
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32.

33. Important System Concepts (continued)

• Modularity
– Process of dividing a system into modules of a
relatively uniform size
– Modules simplify system design
• Coupling
– Subsystems that are dependent upon each
other are coupled
• Cohesion
– Extent to which a subsystem performs a single
function
1.33
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34. A Modern Approach to Systems Analysis and Design

• Systems Integration
– Allows hardware and software from different
vendors to work together
– Enables procedural language systems to work with
visual programming systems
– Visual programming environment uses
client/server model
1.34
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35. Your Role in Systems Development

• Study problems and needs of an organization
• Determine best approach to improving organization
through use of:
– People
– Methods
– Information technology
• Help system users and managers define their
requirements for new or enhanced information
systems
1.35
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36. Developing Information Systems and the Systems Development Life Cycle

• Systems Development Methodology
– A standard process followed in an organization to
conduct all the steps necessary to
• analyze
• design
• implement
• and maintain information systems.
1.36
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37. Developing Information Systems and the Systems Development Life Cycle (continued)

• Systems Development Life Cycle
– Series of steps used to manage the phases of
development for an information system
– Consists of four phases:
• Planning and Selection
• Analysis
• Design
• Implementation and Operation
1.37
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38. Developing Information Systems and the Systems Development Life Cycle (continued)

– Phases are not necessarily sequential
– Each phase has a specific outcome and deliverable
– Every company customizes the life-cycle model to
its individual needs
1.38
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39. Phases of the Systems Development Life Cycle

1. Systems Planning and Selection
–
Two Main Activities
Identification of need
Investigation and determination of scope
2. Systems Analysis
–
Study of current procedures and information systems
1.39
Determine requirements
Generate alternative designs
Compare alternatives
Recommend best alternative
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40. 41. Phases of the Systems Development Life Cycle (continued)

3. System Design
–
Logical Design
–
Concentrates on business aspects of the system
Physical Design
Technical specifications
4. System Implementation and Operation
–
Implementation
1.41
Hardware and software installation
Programming
User Training
Documentation
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42. Phases of the Systems Development Life Cycle (continued)

43. Alternative Approaches to Development

• Prototyping
– Building a scaled-down working version of the
system
– Advantages:
• Users are involved in design
• Captures requirements in concrete form
1.43
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44. Alternative Approaches to Development (continued)

• Computer-Assisted Software Engineering
(CASE) Tools
– Automated software tools used by systems
analysts to develop information systems
– Can be used throughout SDLC
– Product and tool integration is provided through a
repository
1.44
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45. Alternative Approaches to Development (continued)

– General types of CASE tools
• Diagramming tools
• Computer display and report generators
• Analysis tools
• Repository
• Documentation generators
• Code generators
1.45
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46. Alternative Approaches to Development (continued)

• Joint Application Design (JAD)
– Users, Managers and Analysts work together for
several days
– System requirements are reviewed
– Structured meetings
• Rapid Application Development (RAD)
– Utilizes prototyping to delay producing system
design until after user requirements are clear
1.46
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47.

48. 49. Approaches to Development (continued)

• Participatory Design (PD)
– Emphasizes role of the user
– Entire user community can be involved in design
• Agile Methodologies
– Focuses on
• Adaptive methodologies
• People instead of roles
• Self-adaptive development process
1.49
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50. Summary

• Information systems analysis and design
– Process of developing and maintaining an
information system
• Modern approach to systems analysis
– Process-oriented
– Data-oriented
1.50
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51. Summary (continued)

Role of Systems Analyst
Systems Development Life Cycle (SDLC)
› Systems Planning and Selection
› Systems Analysis
› Systems Design
› Systems Implementation
1.51
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52. Summary (continued)

• Alternatives to Systems Development Life Cycle
– Prototyping
– Rapid Application Development (RAD)
– CASE
– Joint Application Design (JAD)
– Participatory Design (PD)
– Agile Methodologies
1.52
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