A number of clients ask me "how many people do you think use BI." It's not an easy question to answer, it will not be an exact science and will have many caveats. But here we go:

1. First, let's assume that we are only talking about what we all consider "traditional BI" apps. Let's exclude home grown apps built using spreadsheets and desktop databases. Let's also exclude operational reporting apps that are embedded in ERP, CRM and other applications.

2. Then, let's cut out everyone who only gets the results of a BI report/analysis in a static form, such as a hardcopy or a non interactive PDF file. So if you're not creating, modifying, viewing via a portal, sorting, filtering, ranking, drilling, etc, you probably do not require a BI product license and I am not counting you.

3. I'll just attempt to do this for the US for now. If the approach works, we'll try it for other major regions and countries.

4. Number of businesses with over 100 employees (a reasonable cut off for a business size that would consider using what we define as traditional BI) in the US in 2004 was 107,119

5. US Dept of Labor provides ranges as in "firms with 500-749 employees". For each range I take a middle number. For the last range "firms with over 10,000" I use an average of 15,000 employees.

6. This gives us 66 million (66,595,553) workers employed by US firms who could potentially use BI

7. Next we take the data from our latest BDS numbers on BI which tell us that 54% of the firms are using BI which gives us 35 million (35,961,598) workers employed by US firms that use BI

8. Then we make the following, unscientific, but educated guesses

   a. 20% of workers in any business can be considered "decision makers"

   b. 1/10th of them are strategic decision makers. Our latest BI maturity survey assumes that 50% of the strategic decision makers use BI, but a large number of respondents disagreed so we'll lower that number to 40%

   c. 8/10 of the decision makers are tactical and operational decision makers. The same BI maturity survey assumed that 25% of them use BI, and a quite a few of the respondents disagreed so we'll lower that number to 20%

9. That gives us 1.5 million (1,582,310) of workers in the US using traditional BI apps, or just over 2% (2.37%) of the total number of employees from these firms. I'd bump it up (unscientifically) to 3%-4% to adjust for growth since 2004.

I think that's a very low number, I would've guessed off the top of my head that it was closer to 6% or 8%. So please let's start a dialog where I might've gone wrong in my assumptions.

Also, BI vendors, please send me your stats on the number of individual licenses that you have (I'll keep them under NDA), and I'll triangulate the numbers.

Boris also blogs at http://blogs.forrester.com/boris_evelson/.