Defining business requirements for BI is a challenge because people tend to think just about data and reports or dashboards (and rapidly get overwhelmed by the near infinite potential for analysis that terabytes of data bring), losing sight of what that information can do for their business. Good BI is not about bringing complicated reports or cool dashboards to end-users: it's about understanding how well your business is going so that you can make the right decisions.
This is how I would recommend you go about defining BI requirements:
Step 1: Identify which KPIs drive the business:
- Basically what this is about is working out what tells us the business is performing well (or badly) and what we base our decisions on.
- To identify these KPIs, you can look at the WHO (who needs BI information?), WHAT (what information do they need?), and SO WHAT (what are they going to do with it?).
As a Business Unit Manager (WHO), I need to know how our products are currently selling against this year's profit targets (WHAT), so that I can take actions such as retiring a poor-performing product and concentrate resources on high-performing ones (SO WHAT)
=> In this example the KPI would be product profitability.
Step 2: Define how KPIs will be measured:
- This is about putting clear definitions and formulas behind the KPIs and working out which transactional data is actually required to provide the result.
- This is also the step where you define dimensions (e.g. time dimensions such as Fiscal Year, Months, Days, etc.) and units (e.g. $, %).
In the example:
You could define profitability as ratio of profit on revenue. Then this number can be calculated for for year to date, month to date, variance against target, rolled-up by product lines, etc. This tells you which data you need (sales revenue and cost), how you need to calculate the KPI and the dimensions you would need to include.
Step 3: Define how results will be presented:
- This is where you look at ways for information to be accessed and presented (static or dynamic reports, dashboards, etc.) and how you can leverage a particular technology.
Finally, when it comes to prioritisation, it should based on which KPIs drive high-impact decisions. Start with a few and do them well (get the definitions, formulas and dimensions right) - in any case you can't effectively make good decisions using 50 measurements, it's better to have a few but of high quality.
Otherwise, as for other projects, I'd recommend you facilitate this exercise as part of a workshop with key business stakeholders and make sure people have ownership for driving this to successful completion.