Systems Investigation and Analysis

1
Systems Investigation and Analysis

• Chapter 11
• (Creating new system or modifying existing
  business system)

2
Principles and Learning Objectives

• Effective systems development requires a team
  effort of stakeholders, users, managers, systems
  development specialists, and various support
  personnel, and it starts with careful planning.
• Identify the key participants in the systems
  development process and discuss their roles.
• Define the term information systems planning and
  list several reasons for initiating a systems
  project.
• Identify important system performance
  requirements for applications that run on the
  Internet or a corporate intranet or extranet.
• Discuss three trends that illustrate the impact
  of enterprise resource planning software packages
  on systems development.

3
Principles and Learning Objectives

• Systems development often uses tools to select,
  implement, and monitor projects, including
  prototyping, rapid application development, CASE
  tools, and object-oriented development.
• Discuss the key features, advantages, and
  disadvantages of the traditional, prototyping,
  rapid application development, and end-user
  systems development life cycles.
• Identify several factors that influence the
  success or failure of a systems development
  project.
• Discuss the use of CASE tools and the
  object-oriented approach to systems development.

4
Principles and Learning Objectives

• Systems development starts with investigation and
  analysis of existing systems.
• State the purpose of systems investigation.
• Discuss the importance of performance and cost
  objectives.
• State the purpose of systems analysis and discuss
  some of the tools and techniques used in this
  phase of systems development.

5
An Overview of Systems Development
6
Participants in Systems Development
7
Information Systems Planning
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Establishing Objectives for Systems Development

• Performance objectives
• Output quality or usefulness
• Output format quality or usefulness
• Speed at which output is produced
• Cost objectives
• Development costs
• Fixed investments
• Ongoing operating costs
• Uniqueness costs

9
Systems Development and E-Commerce

• Internet technology - enables companies to extend
  their information systems beyond their boundaries
  to reach their customers, suppliers, and
  partners.
• Dynamic Core Business Application that runs over
  the Web - must be reliable and fault tolerant,
  providing continuous availability while
  processing all transactions accurately.

10
Trends in Systems Development and ERP

• ERP vendor as one-stop provider
• Applications to integrate with ERP systems
• External consulting

11
Systems Development Life Cycles(SDLC)
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Systems Development Life Cycles
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The Traditional Systems DevelopmentLife Cycle
14
Advantages and Disadvantages of Traditional SDLC
15
Prototyping
16
Prototyping
17
Advantages and Disadvantages of Prototyping
18
Rapid Application Development (RAD)
19
Reasons for Outsourcing -add
20
Factors Affecting Systems Development Success
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Factors Affecting SystemsDevelopment Success
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Project Management

• Project schedule - details activities, personnel
  and other resources allocated to each activity,
  and expected completion date
• Project milestone - critical date for the
  completion of a major part of the project
• Project deadline - date the entire project will
  be completed and the system will be operational.
  Large projects can be very complex and involve
  scheduling managing thousands of different
  activities some can be worked on at the same
  time, some must be done before others can be
  started
• Critical path -contains all activities with no
  slack that is, all activities that would delay
  the whole project if they were delayed.

23
Use of Project Management Tools
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Use of Project Management Tools
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Computer-Aided Software Engineering (CASE) Tools

• Automate many of the tasks required in a systems
  development effort and enforce adherence to the
  SDLC, thus instilling a high degree of rigor and
  standardization to the entire systems development
  process
• Upper-CASE tools - CASE packages that focus on
  activities associated with the early stages of
  systems development.
• Lower-CASE tools - focus on the later stages of
  systems development and are capable of
  automatically generating structured program code.
  
• Integrated-CASE tools - provide links between
  upper- and lower-CASE packages.

26
CASE Tools
27
Object-Oriented Systems Development

• Object-oriented systems development typically
  involves
• Identifying potential problems and opportunities
  within the organization that would be appropriate
  for the OO approach
• Defining the kind of system users require
• Designing the system
• Programming or modifying modules
• Evaluation by users
• Periodic review and modification

28
Systems Investigation

• In general, systems investigation attempts to
  uncover answers to the following questions
• What primary problems might a new or enhanced
  system solve?
• What opportunities might a new or enhanced system
  provide?
• What new hardware, software, databases,
  telecommunications, personnel, or procedures will
  improve an existing system or are required in a
  new system?
• What are the potential costs (variable and
  fixed)?
• What are the associated risks?

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Participants in Systems Investigation
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Feasibility Analysis
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Systems Analysis
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Identifying Sources of Data
33
Collecting Data
34
Data Analysis

• Data modeling
• Activity modeling
• Application flowcharts
• Grid charts
• CASE tools

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Data and Activity Modeling
Entity relationship
Dataflow Diagram
36
Application Flowcharts
37
Grid Charts
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Requirements Analysis

• Asking directly
• Critical success factors (CSFs)
• The IS plan
• Screen and report layout
• Requirements analysis identifies user,
  stakeholder, and organizational needs for the new
  or modified system. This involves studying
  problems they are having with the current system
  and improvements they suggest.
• When a system is clear-cut and users clearly
  understand their needs for the new system, asking
  them to tell you works well. However, when needs
  arent so clear, the systems analyst must find
  other ways to elicit requirements.
• One approach asks mangers to list factors that
  are absolutely critical to the success of their
  mission such as availability of raw materials,
  a customer list, or knowing the location of each
  technician reporting to him. The analyst can use
  these critical success factors to determine the
  outputs the system should provide. Inputs,
  processing, and performance details could then be
  determined.
• The IS plan addresses long-term IS requirements.
  If this is referred to when identifying
  requirements for a specific system, it is more
  likely that the system will fit into the
  long-term plan.

39
The IS Plan
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Screen and Report Layout
41
Object-Oriented Systems Analysis
42
The Systems Analysis Report
43
Summary

• Systems development team - of stakeholders,
  users, managers, systems development specialists,
  and various support personnel
• Five phases of the traditional SDLC -
  investigation, analysis, design, implementation,
  and maintenance and review
• Systems investigation participants -
  stakeholders, users, managers, employees,
  analysts, and programmers