Why so slow and can it be improved?

Hi,

im in the middle of creating an IO schedule to crunhc through 1k or so lines of IO. as i add to the functionality it increases to become slower and slower as it calcs. it currenlty now calculates what looks like a in a loop 3 times. i appreciate it may not be the most efficiently produced workbook but can anyone help me to improve this or pint out where im going massively wrong?

Thanks