Building and Managing Systems

1
Building and Managing Systems

• Chapter Thirteen (10E)

2
Overview of Systems Development

• Systems development - activities that go into
  producing an information systems solution to an
  organization problem or opportunity
• structured type of problem solving with distinct
  activities
• These activities are present to some extent for
  all of the different ways of developing systems
  described later

3
System Development Process

• Systems analysis
• System design
• Programming
• Testing
• Conversion
• Production maintenance

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Phases of the Systems Development
Analysis Design Programming Testing Conversion Prod Maintenance
Investigation Requirements to components Training Prod Maintenance
Feasibility Evaluate alternatives Conversion
Requirements definition

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Systems Analysis

• Definition - analysis of problem to be solved
  with an information system
• Major tasks
• Understand the problem
• Define the problem
• Identify causes
• Specify solutions
• Feasibility study can problem be solved within
  constraints?
• Establishing information requirements for end
  users
• Deliverables include system proposal, feasibility
  study, user requirements
• Approval by management to proceed
• Role of the end user

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Feasibility

• Technical assess hardware, software, technical
  resources
• Economic will benefits outweigh costs
• Operational Is solution desirable within
  existing conditions?

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Systems Design

• Definition - details how a system will meet the
  information requirements determined by systems
  analysis
• Designer responsibilities
• consider alternate technologies
• manage and control the technical realization of
  the system
• Translate the system requirements into
  specifications that will deliver a system that
  solves the problems determined in systems
  analysis
• Role of end users in systems design

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Examples of Translation of Requirements into
Specifications in the Design Phase

• Design of input files (usually database tables)
• Procedures (the formulas or algorithms that will
  be used to process the inputs into outputs)
• Output files (the files that will contain the
  processed data, or the files that record input
  from customers, employees, suppliers, etc.)
• User interface (the design of windows, menus,
  icons, drop down lists, etc.)
• Interfaces (determination of how the system will
  interact with other systems inputs from other
  systems, outputs to other systems)

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Additional Design Specifications

• OUTPUT
• MEDIUM CONTENT TIMING
• INPUT
• ORIGINS FLOW DATA ENTRY
• USER INTERFACE
• SIMPLICITY EFFICIENCY LOGIC
• FEEDBACK ERRORS
• DATABASE DESIGN
• LOGICAL DATA RELATIONS
• VOLUME, SPEED REQUIREMENTS
• FILE ORGANIZATION DESIGN
• RECORD SPECIFICATIONS

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Designer Specifications

• PROCESSING
• COMPUTATIONS
• PROGRAM MODULES
• REQUIRED REPORTS
• TIMING OF OUTPUTS
• MANUAL PROCEDURES
• WHAT ACTIVITIES
• WHO PERFORMS THEM
• WHO PERFORMS THEM
• HOW
• WHERE

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Designer Specifications

• CONVERSION
• TRANSFER FILES
• INITIATE NEW PROCEDURES
• SELECT TESTING MODULES
• CUT OVER TO NEW SYSTEM
• TRAINING
• SELECT TRAINING TECHNIQUES
• DEVELOP TRAINING MODULES
• IDENTIFY TRAINING FACILITIES
• ORGANIZATIONAL CHANGES
• TASK REDESIGN
• JOB DESIGN
• PROCESS DESIGN
• OFFICE / ORGANIZATION STRUCTURE DESIGN
• REPORTING RELATIONSHIPS

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Role Of End Users in Analysis and Design

• Users drive systems effort
• Must have sufficient control to ensure system
  reflects business priorities and needs
• Functional users drive system information
  requirements
• Users can play an important role in the design
  effort (see preceding slides)

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Completing System Development Process

• Programming Translating needs to Program Code
• Testing Does System Produce Desired Results?
• Unit testing Tests Each Unit Separately
• System testing Do Modules Function as planned?
• Acceptance testing Final Certification
• Test plan Preparations for Tests to be Performed
• Role of the end user in testing

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Conversion

• Strategies for conversion
• Parallel Old New Run Same Problems. Give Same
  Results?
• Direct Risky Conversion to New System
• Pilot Introduce Into One Area. Does it Work?
  Yes Introduce into Other Area
• Phased Introduce in Stages
• Training and Documentation
• Role of end users in conversion

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Production Maintenance

• Production Constant Review by Users
  Operators. Does the system meet its goals?
• Maintenance Upkeep Update Corrections Over
  Time
• Fix problems not discovered during earlier stages
• Make changes to the system dictated by new
  requirements

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SYSTEMS DEVELOPMENT
CORE ACTIVITY
DESCRIPTION
IDENTIFY PROBLEM(S)
SYSTEMS ANALYSIS
SPECIFY PROBLEM
ESTABLISH INFORMATION REQUIREMENTS
SYSTEMS DESIGN
CREATE LOGICAL DESIGN SPECIFICATIONS
CREATE PHYSICAL DESIGN SPECIFICATIONS
MANAGE TECHNICAL REALIZATION OF SYSTEM
PROGRAMMING
TRANSLATE DESIGN INTO CODE
TESTING
UNIT
SYSTEMS
ACCEPTANCE
CONVERSION
PLAN
PREPARE DOCUMENTATION
TRAIN USERS TECHNICAL STAFF
PRODUCTION MAINTENANCE
OPERATE
EVALUATE
MODIFY
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Five Methods to Build Systems

• Five methods
• Systems Life Cycle
• Prototyping
• Application Software
• End-user Development
• Outsourcing
• Each method has the six general steps described
  in the systems development process

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Stages of the Systems Life Cycle

• Oldest method
• Stages correspond to the stages of systems
  development described earlier
• Birth, maturity, death (the cycle repeats)
• Used for TPS, MIS, or large complex systems
• Formal process, controls, deliverables
• Limitations
• Resource intensive (time and money)
• Inflexible and inhibits change (freezing of
  specifications)
• Ill-suited for decision-oriented applications or
  situations where system requirements are vague

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Prototyping

• Definition - process of building an experimental
  system quickly and inexpensively for
  demonstration and evaluation so that end users
  can better determine information requirements
• Iterative design
• Very informal compared to SLC
• requirements are determined dynamically instead
  of frozen in advance
• No distinct phases
• No distinct intermediate deliverables for
  management

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Identify user needs
1.
Develop a prototype
2.
N
Prototype acceptable ?
3.
Y
Use the prototype
4.
Development of a Prototype
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The Attraction of Prototyping

• Prototyping is useful when user requirements are
  uncertain, developing user interfaces, or
  developing interactive applications with multiple
  screens
• Communications between the systems analyst and
  user are improved.
• The user plays a more active role in system
  development.
• Implementation is much easier because the user
  knows what to expect.

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Potential Pitfalls of Prototyping

• The haste to deliver the prototype may produce
  shortcuts in problem definition, alternative
  evaluation, and documentation.
• The users may get so excited about the prototype
  that they have unrealistic expectations of the
  operational system.
• The computer-human interface provided by certain
  prototyping tools may not reflect good design
  techniques.

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Applications Software Packages

• Definition - set of programs that are available
  for sale or lease
• Packages eliminate the need for writing programs
  when building systems also reduces design,
  programming, testing, conversion and maintenance
  work
• When are they appropriate?
• common functions
• limited resources for in-house development
• desktop applications for end users

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Types of Prepackaged Software

• Accounts payable
• Accounts receivable
• Check processing
• Document imaging
• Forecasting and modeling
• General ledger
• Health insurance
• Hotel management
• Human resources

• Job accounting
• Inventory control
• Job costing
• Mailing labels
• Order entry
• Payroll
• Process control
• Route scheduling
• Sales and distribution
• Stock management
• Tax accounting

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Advantages/Disadvantages of Packages

• Advantages
• Speed up of systems development phases
• Periodic enhancements/updates from the vendor
  (reduced maintenance)
• External work is often perceived as superior
• Software costs appear to be fixed
• Disadvantages
• Packages never satisfy all user requirements (70
  is very good)
• costs of customization

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End-User Development

• Definition - the development of information
  systems by end users with little or no formal
  assistance from technical specialists
• End user tools - query languages, report
  generators, graphics languages, applications
  generators, or microcomputer tools

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End-User Development

• Definition - the development of information
  systems by end users with little or no formal
  assistance from technical specialists
• End user tools - query languages, report
  generators, graphics languages, applications
  generators, or microcomputer tools

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Historical Factors That Encouraged End User
Application Development

• The programming backlog
• The widespread use of PCs
• The emergence of 4GLs (spreadsheets, query
  languages, and report generators)
• Increasing popularity of client/server
  architecture

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Typical End User Applications

• Use of spreadsheets
• Management graphics
• Word processing (mail merge)
• Queries and report generation
• Desktop publishing
• Email

• Creating local databases
• Using external databases
• Calendaring, meeting management, and personal
  support

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Benefits and Risks of EUC

• Benefits
• Quicker development
• Good fit to needs
• Efficient utilization
• Acquisition of skills
• Free IS staff time

• Risks
• Poor documentation
• Lack of quality assurance standards and controls
• Islands of information
• Duplication of effort
• Security problems

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Outsourcing Information Systems

• Definition - the practice of contracting computer
  center operations, telecommunications networks,
  or application development to external vendors.
  Older usage of this term meant hiring an outside
  firm to develop a custom system.
• Outsourcing is big business IBM, ATT, EDS, big
  accounting firms are all major outsourcers

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Newer Methodologies

• Newer methodologies
• Joint application development (JAD)
• Rapid application development (RAD)
• Characteristics
• Attempts to speed development by reducing
  documentation involved in SDLC
• Large amounts of prototyping
• Heavy involvement of end users throughout project
• End users often take leadership roles
• Does not skip analysis stage like prototyping
• Lots of team meetings where users and IS
  professionals work together
• Use of many new tools (e.g., Visual Basic, Java,
  C, collaborative software, reusable software)