Repeatability is a very desirable guide. Frequently appropriate models that encompass the existing conditions do not exist because all of the conditions upon which they depend have not been identified. However, we usually have some models that seem to apply to similar conditions. They are appropriate as far as we know . All models are created with only some of the conditions identified, and thereby are only able to predict the average result, not individual results.
Management involves specific results under specific conditions.
In practice, a prudent manager accepts predictions cautiously. A good manager understands that surprise is a common experience. The predictions, or expectations, can be thwarted by unexpected changes like unseasonable weather, disease outbreaks, economic changes, etc . Sometimes a surprise is mysterious, without a clear explanation. Managers must be responsive to immediate conditions , and adjust their expectations and reactions accordingly.