Investigation of Information Systems
1. Definition of an Information System:
An Information System is a combination of hardware, software, people,
procedures and data that provides data processing capabilities for a
business or organization.
More sophisticated information systems provide the decision makers in
a business (eg. the executives or managers) with on-demand reports and
inquiry capabilities as well as routine periodic reports.
2. Capabilities of Information Systems:
All information systems have four essential capabilities:
i. Input can come from:
a. Source data such as recording a transaction or an event (eg. a
bank deposit slip or order form).
b. an Inquiry, which is a request for information (eg. list this
week's sales above $3000)
c. a Response to a prompt (eg. a Y or a N)
d. an Instruction (eg. "Print File", "Save File")
e. a Message to another user on the system (g. intranet mail)
f. a Change (eg. editing a record)
ii. Processing capabilities include:
a. Sorting data (eg. sorting a customer file alphabetically)
d. Retrieving, recording and updating data in storage (eg. a
e. Summarizing processes (eg. totals and subtotals)
f. Selecting processes (eg. select employees that have been
employed for more than 5 years)
g. Manipulating processes (eg. performing arithmetic calculations
and logic operations).
iii. Storage capabilities enable data, text, graphics, voice, sound,
music, and other digital information to be recalled easily for
further processing from secondary storage devices.
iv. Output capability allows the system to produce output in a
variety of forms, such as:
a. Hard copy (eg. reports, documents, messages)
b. Soft copy (eg. displays on monitor screens)
c. Control output (eg. instructions to industrialised robots, or
3. Manual vs Computer-based Information Systems
The definition above implies that information systems are
computer-based. They can be manually operated without the aid of
computers. Manual systems consist of people, procedures and data. Many
information systems are still manual, but many are now computer-based.
Both types use established patterns for work practices and information
4. Example: Payroll System: Manual
The payroll clerk:
a. receives time sheets from supervisors
b. retrieves each employee's record file from the filing cabinet;
c. calculates the gross wage manually with a calculator;
d. manually calculates all deductions to get the net wage;
e. manually types the pay cheque and stub;
f. updates the payroll register (stores every detail of wages paid,
deductions made, etc).