Business Intelligence is the presentation of data from any source within an organisation, to enable the most informed decisions to be made. It is not restricted to multi national corporations.
BI may be achieved using a report generator within administration software, an external reports program or maybe Excel pivot tables. The data may be mined from existing sources, or additional qualifying and analytical information may need to be stored.
Most applications now allow access to their underlying data, but it may be necessary to export data by any available means before importing to an open source.
You should be able to analyse your Sales Value, Volume, Gross Margin, by Product, Product Group, Customer, Geographical Area, Sales Manager and the totals should always be the same. This year / Last year, Like for Like. Sales analyses are essential in determining future marketing spend.
A large part of turnover may be barely profitable, the cost of one department may have become disproportionate, the IT may cost more than an army of clerks (the IT is wrong). Simplistic examples but you need to avoid throwing good money after bad.