Ken Whitaker as a wonderful post at Gantt Head on the use of agile development methods and the compliance with FASB 86.
The notion that agile can be used in the corporate product development environment many times fails to recognize that FASB 86 has impacts on when and how the sunk cost of that product development can be considered a capital expense.
In the non-product world, bounded budget and bounded time result in agile projects having scope as the only variable.
This is called time boxed scheduling.