Meaning
Discrepancies between a calculated forecast and the actual observed outcome reveal the limitations of a planning model. Every time a founder estimates future growth or cost, a predictive error is generated when the real data arrives. This delta is a cardinal measurement of how well the model understands the variables driving the business.
A small error suggests a reliable model, while a large one indicates that the plan is missing a major factor.
Forecast Delta
Measuring the distance between the expected result and the truth helps to refine future guesses. When the forecast delta is analyzed, it shows whether the model is consistently overestimating or underestimating performance. This bias can then be adjusted in the next planning cycle to bring the predictions closer to reality.
A delta that fluctuates randomly is harder to fix than one that moves in a single direction. Identifying the source of this gap often leads to a deeper understanding of the market or the internal operation.
Model Accuracy
Percentage of successful predictions over time defines the trust placed in a specific planning tool. Such model accuracy is the standard against which all new forecasting methods are measured.
Prediction Variance
Spread of errors across different scenarios shows the reliability of the model in various conditions. The prediction variance indicates whether the plan is only good for stable times.