A schematic showing the iteration scheme used in MOFAT. The outermost loop loops through blocks, where each block closes particular switches for parameters it wants to test. Each selected parameter is then looped through, where the effects of temperature, NLTE, and total mass are iterated until the χ² statistic reaches a convergence criterion or a maximum number of iterations. This block can then be looped through, where between loops the region of parameters is centered on the best value and subsequently shrunk by 10%. See Appendix C for a more complete description.