Should I separate Actual and Forecast data into 2 tables?

Question

Forecast and Actual data are both being inputted monthly by human within the same column, yet different calculation rules and business objects

Forecast table:

Actual Table:

Answer 1

One might argue that this is a matter of opinion. However, I think the answer is rather obvious. And the answer is "yes".

Why? Forecast data is much more complicated than actual data. For instance, I have worked with a company that does several budgets for a year, before deciding on the final budget in early January. Then on a monthly basis, updates the budget forecast for the year, taking business conditions into account.

So, a forecast might have information such as:

• as-of-date
• how developed
• who approved it
• what time period it is for
• granularity
• and more

In addition, the actuals and forecast might not be at the same level of granularity. For instance, "forecast" might be by business unit. But the actuals might break down by sales person.

These considerations suggest that the two are different entities and should be stored in different tables in the database.