Compiling the CIO100 is a painstaking task. How it is done and some of the problems of creating it are detailed below.

CIOs often ask of the CIO 100 methodology: "It you're ranking the top 100 organisations by their IT usage; then why not just count the number of users?"

It's a fair point and one that we consider every year. While looking into it, we came up against the same problem that we face every year - how do we define user? Is it someone who has a computer on their desk? Is it someone who has access to a computer, perhaps a shared one? Every year this gets even harder to define as mobile devices like the iPhone and Blackberry increasingly provide mobile access and what about the retail sector with its advanced tills, do they count?

One approach is to ask IT departments for the how many user accounts they have, but this has complications too. How do you split one user account per person from generic accounts?

Some organisations are still shy of letting us know their figures and IT usage, so there are some gaps in the system usage details. In addition to that, many organisations are outsourcing large areas of IT, which again affects the profiles and data. Finally with the credit crisis that gripped the world in 2009 there has been a spate of mergers and acquisitions, not least in the banking sector, a stalwart of the British economy. This too has and will in future affect the listing.

So, back to the methodology, if you compare the number of screens, employees and turnover you will come see how the comparative score adds up.

Business and IT strategy changes very rapidly, and we are well aware of that at CIO, so if there have been major changes to the details of the organisation you are CIO with, please do contact me, the editor of CIO Mark Chillingworth at [email protected]

I'd like to finish by asking you to continue suggestion new methodologies for the CIO 100, as during the first half of 2010 I plan to reassess how we build the listing and welcome suggestions from the community.