Budgeting prototype

[Darin Willits]

On Sun, 2003-09-07 at 22:12, Derek Atkins wrote:
> I think what we're really saying here is that we're talking about
> budgeting the _delta_ within a budget period.  For example, if I
> budget $250 for food, what I'm really saying is that "the sum of all
> 'food' accounts would increase by $250 over the budget period".
> Similarly, if I budget $1250 for my mortgage, what I'm really saying
> is that "the sum of my mortgage liability, tax-expense, and escrow
> accounts are going to change by $1250 over that period".
> 
> So, I see no reason to really look at Income/Expense and
> Asset/Liability accounts any differently if you consider budgeting in
> the form of deltas (change over time).
> 
> Is this an accurate summary?
> 

Yes!!  This is exactly the approach I have been trying to get across,
although not worded nearly as well.

The only problem I can see is how do you give the user a picture of the
overall budget status. (ie over-budget/under-budget).  Does the equation
look like this (for one budget period)? (Td == Total Delta)

(Td Income) - ((Td Assets) + (Td Liabilities) + (Td Expenses)) =
Surplus;

where the "Surplus" indicates whether you are over or under budget. 
Typically this is the value the user will look at to approach $0.00 as
they "tweak" the budget.

Now the tricky part.  What if the user (and I maintain they should be
able to) assigns two *different* account types to one category?  Do we
simplify the above equation to something like (need better nomenclature
--who are the accountants in the crowd?) :

Total Allocations = (Td Assets) + (Td Liabilities) + (Td Expenses);

(Td Income) - (Total Allocations) = Surplus;

If we then forced the user (we could probably do this automatically
based on account type in most circumstances) to assign each category to
one of Income or Allocation we could easily calculate the Surplus
value.  

Does this make any sense?


Darin