nested if optimising

good day all,

i have been trying to crack this for a while now, but i cant seem to do it the file i have is to link how often we order with the lead time and keep a safety stock of a month and a half extra depending on the RC for example if its 1 then i have to keep 1.5 months extra, but if it is 2 then i have to keep 2.5 months extra. i also have to test this against the arriving month so i have 6 categories of RC and 6 categories of Lead time and testing all possibilities resulted in a 36 nested if statements to do it. i will attach the original formula (if u have time to read it) and a small test file , i hope you can help me out since excel is not allowing me to save the formula for it is more than 8K characters i had to save it as binary file.

your help is much appreciated