## Sunday, 23 September 2012

### What can go wrong?

Computers are simple - really simple. Fundamentally, they only deal with two things. Programs and data. If you are running everything on one solitary machine, and that machine is not defective, then it is either the program that is at fault, or the data that the program uses. If the program hasn't been changed since it last ran correctly, then it will be the data that is wrong. Simple.

When your computer connects to other computers, the network comes into play. Computers can get locked out when their passwords expire. This requires manual intervention to reset the user id or change the password. Then you can have network congestion. This when the quantity and/or size of all packets of information exceeds the capacity of the network router to deal with them. Individuals can control their own rates to achieve an optimal network rate allocation. You simply need to apply this formula:

$\max\limits_x \sum_i U(x_i)$   so that  $Rx \le c$

Simple...

You could have damaged cables. So if you work in a large organisation, testing each one to find out if there is a problem could take you many hours. The damaged cable might not even be in your building. One of the network cards could get stuck on transmit mode, leading to excessive network collisions. There could be a software configuration problem - typically DNS or TCP/IP settings can cause many issues. You could also have more than one computer using the same IP address. This can create intermittent problems in communication that can be hard to trace.

All of these problems require a dedicated department that can:
• Monitor the performance of your network
• Keep records of failures
• Keep a map of your network to enable diagnosis
• Diagnose and fix problems
...otherwise known as your IT department.

So if you think you can implement bespoke systems without the support of your IT department, think long and hard, particularly if you plan to use a network that other departments also rely upon. Do you really have a handle on what is required to fix problems you may encounter? Can you accept the consequences if your system causes problems with a network that other departments also rely upon?

There is an IT department for a reason. If you plan to develop on your network, engage them ASAP. They may be able to save you an awful lot of pain further down the road.