Why are there different types of information system?
In the early days of computing, each time an information system was needed it was 'tailor made' - built as a one-off solution for a particular problem. However, it soon became apparent that many of the problems information systems set out to solve shared certain characteristics.
Consequently, people attempted to try to build a single system that would solve a whole range of similar problems. However, they soon realized that in order to do this, it was first necessary to be able to define how and where the information system would be used and why it was needed. It was then that the search for a way to classify information systems accurately began.
How do you identify the different types of information system in an organization?
The different types of information system that can be found are identified through a process of classification. Classification is simply a method by which things can be categorized or classified together so that they can be treated as if they were a single unit. There is a long history of classification of things in the natural world such as plants or animals, however, Information systems are not part of the 'natural' world; they are created and acquired by man to deal with particular tasks and problems.
The classification of information systems into different types is a useful technique for designing systems and discussing their application; it not however a fixed definition governed by some natural law. A 'type' or category of information system is simply a concept, an abstraction, which has been created as a way to simplify a complex problem through identifying areas of commonality between different things. One of the oldest and most widely used systems for classifying information systems is known as the pyramid model; this is described in more detail below.
How many different kinds of information system are there?
As can be seen above, there is not a simple answer to this. Depending on how you create your classification, you can find almost any number of different types of information system. However, it is important to remember that different kinds of systems found in organizations exist to deal with the particular problems and tasks that are found in organizations. Consequently, most attempts to classify Information systems into different types rely on the way in which task and responsibilities are divided within an organization. As most organizations are hierarchical, the way in which the different classes of information systems are categorized tends to follow the hierarchy. This is often described as "the pyramid model" because the way in which the systems are arranged mirrors the nature of the tasks found at various different levels in the organization.
For example, this is a three level pyramid model based on the type of decisions taken at different levels in the organization.
Three level pyramid model based on the type of decisions taken at different levels in the organization
Similarly, by changing our criteria to the different types of date / information / knowledge that are processed at different levels in the organization, we can create a five level model.
Five level pyramid model based on the processing requirement of different levels in the organization
What are the most common types of information system in an organization?
While there are several different versions of the pyramid model, the most common is probably a four level model based on the people who use the systems. Basing the classification on the people who use the information system means that many of the other characteristics such as the nature of the task and informational requirements are taken into account more or less automatically.
Four level pyramid model based on the different levels of hierarchy in the organization
