Introduction to information systems T. Cornford, M. Shaikh is1 060 2013

System enironment
Figure 3.1: Systems environment.
Activity
Would you consider the economic system of your country as an open system or a closed 
system?
Taking the online book store Amazon as a system embedded in an environment of 
potential purchasers, explain with an example how the control or feedback might work. 
First consider what the inputs and outputs are and what the purpose of the system is. 
Then try to show how information on outputs can ensure more or better inputs. (Hint: If 
outputs are books shipped to people, how can we use that data to improve the number 
of inputs (for example, orders)?
Information systems are by definition examples of open systems – 
although specifying the boundary (what is in and what is outside) 
can be tricky. Thus, information systems have some relations with the 
environment beyond their boundary – accepting inputs and generating 
outputs. For example, a payroll system for a company will:
• take in data about who worked how many days as inputs
• process this data in various ways to calculate how much to pay people 
and how much income tax to deduct 
• generate instructions to a bank to transfer money to the workers’ bank 
accounts as outputs, and tax to the government. 
This process all has some effect on the company’s environment. If people 
are paid on time and correctly there is one effect; if they are paid late or 
too little, there is another!
The principal interactions between an information system and its 
environment can be described as the:
• receipt of signs or signals from the environment as inputs
• storage of the inputs in an organised manner as data
• processing or manipulating the data 
• passing of signs and signals back into the environment as outputs.
Outputs will in general be created in response to inputs – for example, 
a request for some stored data to be processed and displayed. Another 

---

IS1060 Introduction to information systems
42
example might be an order for goods as an input, and instructions to the 
warehouse to dispatch them as output (plus perhaps an instruction to the 
factory to make some more). 
Overseeing this process to check that it operates correctly will be some 
form of control mechanism. Such controls are based on feedback 
– either positive or negative. Within the computer component of an 
information system, this control activity is one of the tasks of software, but 
it must be remembered that information systems are more than computers 
and that control activity (processing feedback) will also be undertaken by 
people.
Control issues are discussed in more detail in Chapter 9 of Curtis 
and Cobham (2008).