1. An automated method for accurately modeling spending, the method comprising the steps of: receiving invoice information and payment information; automatically generating a distribution for a distribution period in response to the invoice information and the payment information, wherein the step of automatically generating a distribution includes matching at least one invoice specified in the invoice information to at least one payment specified in the payment information; automatically transforming the generated distribution from the distribution period to a spending period; receiving spend information for the spending period; and automatically spreading a spending amount specified in the spend information over the transformed distribution.