# Formulas and their effects on model performance

## Details of known issues

The content in this article has not been evaluated for all Anaplan implementations and may not be recommended for your specific situation.

Informative post! Thank you @DavidSmith.

Question for you regarding "Calculations are over non common dimensions":

Taken to the logical extreme, if many intermediate line items are used, would this not adversely impact model performance by reducing Anaplan's ability to perform parallel calculations? For instance, if you have many intermediate line items for a formula that could otherwise be done in a single line item, is it possible that performance could be worse?

My goal here is to understand if performance is so adversely impacted by calculating over non-common dimensions that I should *never* do it, or whether it depends. If the answer is "it depends", then it would be helpful to understand the nuance, since it's difficult to measure the amount of time associated with the recalculation of a specific complex formula in a project setting where there's a lot going on in a model.

Hi

Thanks for your quesiton and interest in the post

The intermediate steps will calculate in parallel and after that there will be a smaller calculation pulling in the intermediate values to the original line item.

So we have created a non-parallel sequence, but the reduction in calculation time for the intermediate, by reducing the dimensions the line item calculates over, is much greater than the extra step to reference the intermediate calculation.

The other benefit of intermediates is when only one of the values changes only the intermediate is recalculated and the overall calculation is much lower.

So, following the DISCO princples of model building, try and group calculartions together with like structures.  It will give the benefits above and abover it provides a single place for all calculations that relate to the common dimensionality

I hope this helps

David

Thanks for this informative post @DavidSmith!

I have a question about something that confuses me. It's best practice to set non-long formulas in modules instead of long ones. It also meets the auditable standard of PLANS.

But if we split the formulas by creating intermediate line items, wouldn't that increase the size of the model while doubling or tripling the amount of cells? From my point of view it might be better to create a bit longer but auditable formulas than to increase remarkably the amount of cells.

Aykut

Version history
Last update:
‎06-03-2022 05:18 PM
Updated by: