Unconventional Cash Flow

A series of inward and outward cash flows over time in which there is more than one change in the cash flow direction. This contrasts with a conventional cash flow, where there is only one change in cash flow direction. In terms of mathematical notation - where the - sign represents an outflow and + denotes an inflow - an unconventional cash flow would appear as -, +, +, +, -, + or alternatively +, -, -, +, -.

The term is particularly used in discounted cash flow (DCF) analysis. An unconventional cash flow is more difficult to handle in DCF analysis than conventional cash flow since it may have multiple internal rates of return (IRR), depending on the number of changes in cash flow direction.

In real-life situations, examples of unconventional cash flows are abundant, especially in large projects where periodic maintenance may involve huge outlays of capital. For example, a large thermal power generation project where cash flows are being projected over a 25-year period may have cash outflows for the first three years during the construction phase, inflows from years four to 15, an outflow in year 16 for scheduled maintenance, followed by inflows until year 25.