The Novice's Approach to... "What... If Analysis"
When folks talk about what they want to do with business intelligence, "What... if?" analysis is rarely number one on their lists. On the other hand, it is most folks' number two (usually after "provide users with easier access to data" and before "predictive analysis"). It's interesting, however, that "What... if?" analysis is rarely actually performed in real life.
WHAT IS "What... If" ANALYSIS?
What if analysis is exactly what it sounds like - looking at your data as if some situation was true. For example
WHAT would our profits be IF our unit cost was reduced by 2%.
WHAT would happen to our profits IF we spent 5% more on marketing but it produced a 5% increase in revenues? A 0% increase?
WHAT would each salesperson have produced last year IF we didn't carry our vanilla-flavored chocolate pudding?
WHY IS IT SO HARD?
It isn't.
AN EXAMPLE
Here is a simple example from QlikView that asks the question, "What would happen if our revenues changed by X%?"
In this example, the user can modify the revenue forecast. As the example shows, if you don't expect there to be any changes in revenue, the 'as is' and 'simulation' amounts will exactly equal each other.
On the other hand, let's see the predicted results of 25% increase in forecast revenues:
Now the user can see the difference graphically. This analysis could also, of course, be shown as a table so users could analyze the actual, What..If figures.
BEHIND THE SCENES
You can do What If analysis with any BI tool. The trick is to insert prompts and variables into your reports that users can change. Then, use those variables as figures or multipliers in your reports. Just about every BI tool supports the use of variables.
In the example above, the slider bar sets a variable called vRevenueIncrease. The magic is in the graph. Basically, the graph charts two lines: the forecast revenue AND the forecast revenue * vRevenueIncrease.
While we've shown a slider bar, most BI tools give you a few ways to enter variable values.
BE CAREFUL
When you do "What..If" analysis, make sure to consider the cause and effect relationship between variables. For example, if you model a 5% increase in revenue you'll show a great improvement in profitability. However, that profit improvement is really illusory if you haven't also modeled the increase in cost of goods sold and the other costs associated with an increase in sales (By the way, a 5% increase in sales price, as opposed to unit sales, might properly show the related profit increase so long as the increased sales price wouldn't also lead your customers to purchase less).
Also note that, most BI tools make it difficult to store variables between sessions or to save multiple scenarios. So, if you want to keep what you've created, export it, print it, or lose it.
Anyhow, thanks for your time. Feedback is encouraged & appreciated.
















