API for precision Vs API for accuracy

[srini1978]

We should also decide if we are building the API for precision vs building the API for accuracy. Simply defined from Yannick's email (Amadeus)

• Measurement for action requires precision: results needs to be comparable (i.e. is A same, better or worse than B ?) to select one over the other.
• Measurement for monitoring require accuracy: results needs to be close to reality (in term of value and trend) but allowing some fluctuations over time.

At this point based on various discussions we have had, it does seem like that we are targeting precision Vs Accuracy. Precision is about getting same results over multiple iterations of the tool.

This decision affects the granularity of the API #23 . If we go with this approach we could make some decisions on #22 by choosing stories for v1 Scope that speak to a customer scenario and allow the calculations to provide repeatable iterations before and after making "sustainability" changes. Examples of such a scenario are given by Amadeus here #24