Improve code efficiency

Good day mates,


I'm working on this spreadsheet that is supposed to give a potential customer (owners of ship fleets) an overview of investing in a system that reduces fuel consumption. When I've set up the details for each ship (Implementation Plan), currency, interest rate(DashBoard), etc... and press "Update" (which runs my macros), it can take up to 2 minutes for the sheet until the final calculations are finished.

I'm not a skilled VBA coder, so the code in the macros is not all by me. Hence my question; is there any way to shorten the calculation cycle? Somehow I would have thought Excel 2007 would do this quite quickly on a decent computer. I would copy the code into here but the whole thing is in 3 or 4 different macros.


Also, a bit unrelated but still: If any of you are businessmen with education or experience, I would appreciate if you could take a look at the sheet and see if there's anything you can suggest for improvement. My aim with this sheet is to be as clear as possible and make the whole thing easy to understand. But I also may be missing some important aspects of what the investor wants to know? I'm definitely interested in any criticism you can give.


And finally, if anyone is up for a challenge, I know that for some reason if I change the currency type, (with everything else unchanged) I dont get the same ROI and IRR percentages. They should of course be exactly the same no matter if the figures are displayed in EUR or USD(note that one needs to "Update" in order to recalculate with a new currency). I just can't seem to figure out where I'm doing the mistake. Maybe I've spent too much time on this already, hehe.


Any assistance greatly appreciated!
/Eggert

The pro's use excel functions and only use VBA when you can find a excel solution
There are many loops and that always slows every things down. I seen workbooks larger than yours convert to excel functions with no code that do increaibly calculations in seconds.

functions are the way to go to save minutes

circular references with interations
Sorry about the news.Only had a quick peruse and it didnt look good but I have a look/critque and see what I can find

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You don't need all those words such as long macro, something like" improve ode efficiency"

Hi Eggert
Ive attached an example from the master John Walkenback to show how it works and eleminate the need for a looping vba code.

Eggert
Now that you have had a look at the circular references
look at this attacment
It what you will need to do
To help I'll need all your calx's

No it was just an example to show how complex caterinary calx can be solved by using named ranges interations and circular references and then graph the results.
What are your formulae ?

Its very hard to follow the functions/code even with tracing so if you have the forumlas it will make it easier