Organisational Information System (OIS) management strategies

Organisations working with information systems require strategies to allow them to control access to data, to protect their systems and data from unauthorised access, and to improve and update their information systems in response to changes in working practices or technology.

There are five key areas which organisations must consider as part of the development and operation of organistional information systems. These are:

• network strategy
• security strategy
• backup strategy
• upgrade strategy
• software strategy

Since we’ve only looked at Network strategy, I will begin there.

Basically a network strategy allows an organisation to manage how data is distributed across the enterprise. It’s necessary for an organisation to function correctly.

There are different types of network, there’s a chance we can be asked about these in the exam so it’s worth learning it.

• local-area networks (LANs) : This is where the computers are in close proximity (that is, in the same building).
• wide-area networks (WANs) : The computers are farther apart and connected by telephone lines or radio waves.
• campus-area networks (CANs) : The computers are within a limited geographical area like a campus etc.
• metropolitan-area networks (MANs) : A data network designed for a town or city.
• home-area networks (HANs) : A network contained within a user’s home that connects media devices, computers and network enabled domestic appliances.
  

The most common of these are LANs and WANs.

Topology

A topology is the physical structure of the network, how the workstations are connected by cable.

The first topology we have looked at is the bus topology. It consists of a main run of cable with a terminator at each end. All the network devices (nodes) are connected to the cable.

 

 Advantages of a bus topology

• It’s easy to implement and extend because all that is needed is a back-bone cable into which the various nodes are attached.
• They’re well suited for temporary networks that must be set up in a hurry and where costs are to be kept to a minimum.
• If one node fails then the network doesn’t fail because the data flows along the bus rather than the individual nodes.

Disadvantages of a bus topology

• The entire network shuts down if there is a break in the back-bone cable.
• They require terminators at both ends of the back-bone cable to indicate the physical end of the network. They absorb the the signals so that they don’t bounce back and interfere with network traffic.
• If the network does have a failure then it’s very difficult to pin point the problem. Sometimes the only way to locate the problem is to move the terminator along the bus, shortening the length of the network until it functions again.

Because of these disadvantages bus topologies are not meant to be used in large building or complexes.

If in an exam you’re asked to describe a bus topology (or any other topology), then it’s a good idea to make a small simplified diagram of the topology with the key parts labelled.

Have I missed anything important out?

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