Dfd for Hotel Management Systems - PDF

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          Managing Information Systems

                            Module 4

          Systems Development Process

                       Lectures and handouts by:
                              Peter M Sol




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Systems development process:
The process of modifying existing systems or either acquiring or
developing new ones. Problem or opportunity must first present itself

Participants in systems development:
                             Management

                                                   Programmers
         Stakeholders

                                Systems
                                 Analyst
                                  (you)             Technical
               Users                                Specialists
                                                      CNE
                                Vendors               MCSE
   Page 479                       and                  A+
                                suppliers
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 Initiating the Systems Development Project          page 481

 Perception of a problem or benefit or opportunity
       •  Problem with existing system
       •  Explore e-commerce opportunity
       •  Increased competition
       •  Need better communication
       •  Merger or acquisition
       •  Organizational growth
       •  Market change
       •  New laws or regulations




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                          ABC Company
THEN
•  Began with two partners and six employees ten years ago
•  Manufactures building products for the home construction market
•  Information system was an entry level bookkeeping system
NOW
•  Markets have expanded across the continent
•  Possible global expansion
•  Two manufacturing plants & one more in planning stage
•  Over three hundred employees
•  Office staff includes:
     •  Controller
     •  2 accounting staff
     •  2 part time clerks to do payroll


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                         ABC Company

PAYROLL SYSTEM:
•  Payroll system needs to adapt
•  Not able to handle government reporting
•  Timesheets for plant employees must be entered by payroll clerks
•  Payroll is often late and up to 20% inaccurate
•  Payroll clerks are working overtime to keep up
•  Sr. management want to initiate direct deposit

Options:
  •  Hire more payroll staff
   •  Upgrade the existing payroll system
   •  Outsource the payroll department



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   Initiating the systems development project
    ABC’S ISSUES…
   Perception of a problem or benefit or opportunity
           •  Problem with existing system
           •  Explore a new opportunity
           •  Increased competition
           •  Better use of information
           •  Organizational growth
           •  Merger or acquisition
           •  Market change
           •  New laws or regulations


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Information Systems Planning
Translate strategic and organizational goals into systems development
initiatives

Major advantage is a long-range view of information technology use in
an organization

How should the infrastructure be developed over time
Ensures better use of resources

                   Organization’s Strategic plan and
                    corporate goals and objectives


                               IS Planning

                        Systems Development Initiative

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    Information System Planning Steps:                   page 483

    •  Identify IS Projects
             Determined from strategic plan
             Can include previously unplanned systems projects

    •  Set priorities and select projects

    •  Analyze resource requirements

    •  Set schedule and deadlines

    •  Develop IS Planning Document



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IS Planning involves

Creative Analysis:
       Investigating new approaches to existing problems

Critical analysis:
    •  Unbiased questioning of effective and efficient relationships of
         system elements

    •  Going beyond automating manual systems

    •  Questioning statements and assumptions
        Identify user needs
        Maintaining goals and objectives

    •  Identify and resolve conflicting objectives
         All stakeholders are included
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Establishing Objectives for Systems Development

Identify Mission Critical systems
   •  TPS
   •  Establish critical success factors
   •  Convert these critical success factors in to specific objectives

Performance Objectives




Cost Objectives


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  Establishing Objectives for Systems Development

  Identify Mission Critical systems


  Performance Objectives
     •  The quality of output
     •  The usefulness of output
     •  The quality or usefulness of the format
     •  The speed at which output is generated

  Cost Objectives




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  Establishing Objectives for Systems Development

  Identify Mission Critical systems


  Performance Objectives


  Cost Objectives
    •  Development costs
    •  Hardware investment
    •  Software costs
    •  Ongoing operating costs




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          Traditional Systems Development Life Cycle
                       Systems Investigation


                           Systems Analysis


                            Systems Design


                       Systems Implementation


                 Systems Maintenance and Review
                                          page 487
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The formal SDLC:
   •  Includes formalized methods for project review
   •  Allows for large degree of management control
   •  Reports oriented to assess progress after each phase
   •  Uses formal DFDs for analysis and design and Structured design
       and programming techniques

 Problems with the SDLC
    •  Time consuming (up to 2 years)
    •  User does not use the system until it is nearly complete
    •  Costly
    •  Not really appropriate for small systems or Networks
    •  Generates volumes of paper and specifications
    •  Rigid and inflexible
    •  Hard to change the further along you go

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Alternatives to traditional SDLC: Prototyping              page 490

•  Build a preliminary model of the system for end-user interaction
          and analysis.
•  Can be constructed cheaply and quickly, looks and works like the
          real thing
•  Appropriate for small applications only
•  Iterative process that involves intensive user involvement

Steps in prototyping:

    1.   Identify preliminary requirements;
    2.   Develop a working prototype
    3.   Use the prototype
    4.   Revise and enhance the prototype
    5.   Develop Production Version


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Steps in prototyping:
   1. Identify preliminary requirements;
           •  information needs
           •  problem area
           •  constraints

   2. Develop a working prototype
         on-line screens and reports using small data files.

   3. Use the prototype
         the user evaluates the prototype and recommends
           improvements.

   4. Revise and enhance the prototype
         make improvements until the user is completely
           satisfied. (GO BACK TO 3 until perfect)

   5. Develop Production Version
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Strengths:

•  Takes about 10% - 20% of traditional time

•  Excellent when user requirements are unclear

•  Good for testing and updating GUI’s

•  Good for aiding business visualize information and data flows

•  Allows for early detection of errors and omissions




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Weaknesses:

•  Not suited to complex, high risk systems with large
        transaction volumes

•  Not a substitute for detailed analysis and design.

•  Testing and documentation tend to be ignored.

•  Typically lack internal controls and appropriate security
        features.



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RAD / JAD (reduced application development & joint application
       development)

•  A systems development approach (speeds the application
         development)

•  Uses special tools, techniques and methodologies

•  RAD makes use of JAD

•  JAD involves team approach procedures to analyze and improve
        systems and includes team based decision making

•  Suited for decision support and management systems
•  Not suited for TPS’s
•  User participation is high and includes heavy time commitment
•  Documentation is produced as a by product the completed project

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End-User Development systems

Usually a complement to existing systems development projects

Small, precise projects

Undertaken by business management and users

Uses Desktop applications
      •  DreamWeaver
      •  SQL
      •  Excel macros
      •  MS Access


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 Factors affecting systems development success
 The degree of change associated with the project

 Continues improvement versus re-engineering
        •  Continuous improvement involves minor alterations
        •  Re-engineering involves fundamental changes
        •  The greater the change, the greater the risk of failure


 Common problems from initiating new or modified systems
      •  Fear of job loss
      •  Fear of loss of power or influence
      •  The new system creates more work than it saves
      •  Reluctance to work with techie nerds
      •  Fear that the organization will change
      •  Unwillingness to learn new procedures
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   Project Planning:

   Another key factor in Systems Development Success


   Typical project planning issues:

          •  Solving the wrong problem
          •  Poor problem definition or analysis
          •  Poor communication
          •  Project is too ambitious
          •  Lack of management support
          •  Lack of management or user involvement
          •  Poor testing and implementation
          •  Users cannot use the new system effectively
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Project management tools:                                    page 498

•  Project Scheduler
     •  Who’s doing what and when
     •  Who needs what and from whom and when
     •  Divides the project into small tasks

•  Critical Path
    •  Program Evaluation and Review Technique (PERT)
    •  Creates 3 time estimates for each critical path activity
         (short, likely, long)

•  Gantt chart
        Graphical picture of timelines and sequences

•  CASE (Computer Aided Software Engineering) tools
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                                Pert




Gantt Chart
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Project management tools



CASE (Computer Aided Software Engineering) tools
  Upper CASE tools are automated tools that help with the
     investigation, analysis and design phases

   Lower CASE tools focus on the implementation and
      review phase

Benefits of CASE:
       •  Quality
       •  Productivity Increase
       •  Documentation improvement
       •  Reduced maintenance costs
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Object Oriented Systems Development (OOSD)           page 504

Combines the logic of the SDLC and the power of OOP

The six steps in OOSD are:

1.  Identify problems or opportunities appropriate for OO
    approach. Usually projects that modify existing programming
    modules

2. Define what kind of system that the user requires
   Use CASE to modularize the work environment into Objects

3. Design the new system


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Object Oriented Systems Development (OOSD)
Combines the logic of the SDLC and the power of OOP

The six steps in OOSD are:

4. Program the modules
   •  Modify existing modules or adding new ones
   •  Use OO Programming

5. Evaluation by Users
   •  Test the new system for accuracy, ease of use
   •  Compare with stated objectives

6. Periodic review and modifications


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       Traditional Systems Development Life Cycle

                   Systems Investigation


                     Systems Analysis


                      Systems Design


                  Systems Implementation


             Systems Maintenance and Review
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SDLC – Systems Investigation                   page 502

Answers the following:
     •  What is the problem or opportunity
     •  What hardware, software, databases, personnel,
             telecommunications or procedures are needed
     •  What are the costs
     •  What are the risks

The Investigation team
      •  IS personnel
      •  Management
      •  Users
      •  Stakeholders

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Feasibility Analysis          “TELOS”                page 503

•  Technical feasibility
        Can it be done with current technology

•  Economic feasibility
        Does the project make financial sense

•  Legal feasibility
         Are there any legal impediments to the project implementation

•  Operational feasibility
        Can the project work both logistically and motivationally

•  Schedule feasibility
        Can the project be completed in a reasonable time


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     Feasibility analysis uses capital budget models

         •  Net Present Value                             page 484
         •  Cash Flow
         •  Cost Benefit analysis




     Systems Investigation Report

         •  Summarizes the Investigation phase
         •  Review of Goals and Objectives
         •  Includes feasibility analysis
         •  Project Costs and Benefits
         •  Recommends a course of action (continue or quit)
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SDLC – Systems Analysis                           page 505

Starts with the goals of the organization, and how the existing
       system meets those goals

The 5 steps in the analysis phase include:

1. Assemble participants
      •  Users, IS personnel, Management
      •  Develop objectives
      •  Develop timelines

2. Collect appropriate data and requirements


3. Analyze data
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SDLC – Systems Analysis

The 5 steps in the analysis phase include:

1. Assemble participants

2. Collect appropriate data and requirements
      •  Interviews (structured & unstructured)
      •  Direct observation
      •  Questionnaires
      •  Statistical sampling
      •  Follow-ups and clarifications

3. Analyze data
      •  Use Entity Relationship (ER) diagrams
      •  Uses Data Flow Diagrams (DFD)                 page 489
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   process                                           Flow
               Entity I/O            Storage

     Data flow diagrams: part of the data analysis phase
     Logical DFD
        •  How the data should flow
        •  Used to describe current system
        •  Used to show optimal or new system

     Physical DFD




     Application Flowcharts
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  process                                             Flow
              Entity I/O           Storage

Data flow diagrams: part of the data analysis phase
Logical DFD

Physical DFD
   •  Shows how current procedures work
   •  Shows how new procedure or system will work
   •  Identifies specific source documents
   •  Shows who or what does the process

Application Flowcharts
  •  Shows the relationship between applications and systems
  •  Show the relationships and the processes in logical order

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4. Analyze Requirements
   •  Determine the needs of the organizational participants
   •  Make sure everyone knows the goals and objectives of
       the organization
            •  Users
            •  Management
            •  Stakeholders
   Tools used in this phase
       •  Ask directly
       •  Use critical success factors from management and users
       •  Develop screen and report formats

5. Prepare an Analysis Report



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4. Analyze Requirements

5. Prepare an Analysis Report                   page 514
   •  Strengths and weaknesses of existing system
   •  New system requirements
   •  Organizational requirements of the new system
   •  Project priorities
   •  What will the new system do to solve the problem that
        we started with




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   The SDLC is Report Oriented

   Investigation Report                              Investigation

   Preliminary Analysis Report
   Analysis Report                                  Analysis

   Design Report
   Programs and Status Report                        Design

   Acquisition Proposal
   Project Completion Report                         Implementation

   Post Implementation Review
   Request for Maintenance                           Maintenance



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 Appendix: How to draw flowcharts
Wailea Customer Payment System
A hotel customer wishing to pay for a room, a set of rooms, or special
services can pay with a credit card, cheque, or cash. The customer pays at
the cashier’s desk in the hotel lobby. If the payment is by credit card, the
cashier obtains a credit authorization from the credit card company using
swipe card technology at the cashier’s desk. The customer signs the credit
authorization slip once the credit is approved, and the customer is then
issued a receipt. If the credit is not approved, the card is returned to the
customer. If payment is by cheque, the cashier is required by hotel policy
to see some other form of photo-identification with the customer’s
signature (usually a driver’s license) and to record the main number from
this other form of identification on the back of the cheque. The customer is
then issued a receipt. If payment is by cash, the cashier deposits the funds
in the cash register and gives a receipt to the customer.

Required
Draw a physical data flow diagram for the Wailea Customer Payment
System.
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Pause this presentation and download the word file:
 ”Flowchart How to”. Once you have the file,restart
this presentation and we’ll review a data flow diagram
and a system flow chart




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    Reviewing:

    Wailea Customer Payment System




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