CSE1IS Information Systems Week 1 Lecture 2 Components of an IS

1. Components of an Information System:

5 essential components:

The prescribed text , Shelly, Cashman and Rosenblatt, presents a model of (computerised) IS based on five major components (see figure 1-8).  The text also discusses the relationship between IS and levels of managerial decision making. A summary of this material is presented below. The role of people in IS development and use, and possible classifications and examples of  IS are discussed in much more detail in the rest of the theory  for this week.

people

• end -users
  • interact directly with an information system
  • supply (input) data and receive information
• management
  • information from an information system (output)
  • should form an aid to managerial decision making
• IS professionals
  • those who develop, implement and maintain information systems.
    (see figure 1-29 for a typical IT department structure)

processes (procedures)

• The tasks and business functions that users, managers, and IT staff members perform to achieve specific results.
• Business processes represent the day to day business operations (see figure 1-11).     

hardware

• the physical equipment
  • computers
  • printers
  • communication devices
  • scanners
    .............

software

• systems software
• application software
  

data (files or tables)

•  electronic storage of data
• information is obtained directly or indirectly from the system file(s)
• see figure 1-10 for a simple example

2. Some Information System Examples:

A. The Mirridong Patient Incidence System

Mirridong is a home for elderly blind people (patients) at Bendigo. They are required to keep track of incidents that occur within the home. An example of an incident is when a patient falls over and hurts themselves. In the tutorial you will be looking at the computer program used to record these incidents.

The Mirridong system in a DOS application and consists of 3 types of files:

• program      .EXE      (1 program file)
• data      .DBF      (lots of linked files)
• index      .NDX      (about one per data file)

B. The Prompt Computer Solutions

Prompt Computer Solutions assemble computer systems from individual components.
Examples of components are video adapters, monitors, memory, motherboards etc.

Prompt is developed in Microsoft Access and runs as a series of windows. The system consists of just 1 file:   

• prompt3.mdb

C. STROMS:

STROMS (Student Tutorial and Registration and Online Management System) is an online web-based system developed by third year Major Project students.You will be looking at two interfaces into the system: Lecturer and Student. (There is a third interface - who would that be for?)

D. AgShow:

Description: Typical Agricultural Show competitions are organised into sections, subsections and classes, with the classes being the individual competitions. Examples:
    section:
    subsection:
    class:

People:

Procedures:

Hardware:

Software:

Data:

3. Attributes of a Good Information System:

• clear screen layout
• menu structure/hierarchy:
• data entry:
  • allowance for previous required entries
    eg.Can a new customer be declared during entry of an order
  • validation on entry
    eg. cannot enter a customer number for an order that does not exist in the customer file
  • scroll bar selection ensures only correct data can be selected.
• reports:
  • on all data
  • on selected records
  • summary
  • correct ordering
  • allowance for exception reports (often once-off reports generated to answer a specific need.)
• allow short cuts for experienced users
  eg. use of function keys
• inbuilt backup/recovery?
• In a good Information System the user should never be confused about what they are to do.

4. Typical Retail Business Flow of Forms:

1. Order Form to suppliers
• itemised - one line per item
2. Invoice from suppliers
   • arrives with the goods
   • itemised
   • qty shipped + qty on back order
3. Monthly Statement (bill) from suppliers
   • cross-referenced to unpaid invoices
   • aged balances for 30, 60, 90+ days
4. Receipt from supplier on payment
5. Order Form from customer
6. Picking Slip (or Packing Slip)
   • itemised
   • used by employee to gather shipment goodies
   • box to enter qty actually packed
   • cross-reference to customer's order form#
7. Invoice to be sent to customer
   •  constructed from packing slip
     ( in some businesses it is the packing slip)
   • itemised containing full details on every item ordered
8. Monthly Statement to customers who have not paid their invoices
   • cross-referenced to outstanding invoices
   • aged balances for 30, 60, 90+ days
9. Receipt to customers on payment

References:

• Shelly, Cashman & Rosenblatt, Systems Analysis and Design, 6th Edition,  Course Technology, 2006.