Saving file space by simplifying formulae

Hi - I've built a spreadsheet tool to analyse a MS project plan to determine resource demands based on a RACI chart. The upshot is that I have multiple cells (thousands) with complex fomulae that a) take up a lot of space and b) take an age to process.
The main formula is:
=IF(AND((OR(AND(TEXT(AF$7,"yyyymmdd")>=TEXT($D1990,"yyyymmdd"),TEXT(AF$8,"yyyymmdd")>=TEXT($E1990,"yyyymmdd"),TEXT(AF$7,"yyyymmdd")<=TEXT($E1990,"yyyymmdd")),AND(TEXT(AF$7,"yyyymmdd")<=TEXT($D1990,"yyyymmdd"),TEXT(AF$8,"yyyymmdd")>=TEXT($E1990,"yyyymmdd")),AND(TEXT(AF$7,"yyyymmdd")<=TEXT($D1990,"yyyymmdd"),TEXT(AF$8,"yyyymmdd")<=TEXT($E1990,"yyyymmdd"),TEXT(AF$8,"yyyymmdd")>=TEXT($D1990,"yyyymmdd")),AND(TEXT(AF$7,"yyyymmdd")>=TEXT($D1990,"yyyymmdd"),TEXT(AF$8,"yyyymmdd")<=TEXT($E1990,"yyyymmdd"))))),(7.2* (NETWORKDAYS(HLOOKUP(CONCATENATE(AF$7,"S"),$H$9:$AE$1980,$G1990,FALSE),HLOOKUP(CONCATENATE(AF$7,"E"),$H$9:$AE$1980,$G1990,FALSE)))*VLOOKUP(VLOOKUP($F1990,Lookups!$G:$AE,AF$9,FALSE),Lookups!$A:$B,2,FALSE)),"").

Essentially this calculates the actual effort in hours between start-end dates, driven by a RACI (responsible, accountable, consulted, informed) value that indicates the percentage effort applied to the given task, e.g. Accountable 20% effort, Responsible, 80%. Calculated hours are stored in a large matrix of role and time against project task, for later summary.

Two questions: 1) can I simplify the formula and/or 2) can I somehow store it once and somehow parameterise it/call it as a subroutine? I'm guessing both options would save space and maybe processing time. Any thoughts welcome.
Thanks,
Graham

I'm not sure why you are converting all those dates to text values and then comparing them - can't you just compare them directly, so the first line of your monster formula would become:

=IF(AND((OR(AND(AF$7>=$D1990,AF$8>=$E1990,AF$7<=$E1990),AND( ....

much shorter already !!

Hope this helps.

Pete

Thanks Pete. Someone else asked the same question. It's because tasks can straddle start and end dates of the pigeon holes I accumulate the values in. I'm sure I've missed something, but I think the sequencing of unpicking years, months and dates is important and I couldn't figure a better way.
Graham

ok - let me think about that. Maybe I've over-complicated things.

Gotcha!