Fiscal month is typically defined by your accounting department. Quite frequently, it is the same as calendar month, but not necessarily. I've seen fiscal periods that end a day or two before the calendar month, and the first month of the fiscal year in May or June.
That said, either way it is possible.
If the fiscal month is the same as the calendar month, you can use a group by query with something like this:
SELECT Year(FiscalDate) & "_" & Month(FiscalDate) as FiscalPeriod, UnitDesc, Sum(UnitsProduced) as SumOfUnits
Group By Year(FiscalDate) & "_" & Month(FiscalDate), UnitDesc
where FiscalDate is the production date of the units. If your fiscal dates don't fall on the month boundaries you probably need to create a table defining the fiscal months and join to it. If the fiscal months don't line up with calendar months, you can do the same with an independent table, or do a calculation to derive the fiscal month.
Does this help?