Hi,
Based on database theory, the complex model should be normalized. But
in this specific situation, what I want is input data once, then use
references to compare them in different decision models.

The typical way to do it is same month by years, same year data for
seasonal patterns, etc.

The complexity would be resolved easily by programmig a C++ or C#
application to generate the spreadsheets in fly.

Do you think that would worth it? How to adjust the business (cost,
benefit, future usages, etc.)?