Formulas: Are there long formulas, such as complex IF THEN ELSE statements?
When is this a problem?
If you can't explain the purpose of a formula in one sentence, the formula is too long.
Why is this a problem?
Long formulas, such as complex IF THEN ELSE statements, are difficult to understand, audit, and maintain. Complex formulas use valuable processing time and require the engine to work harder than necessary.
How to correct:
Simplify complex IF THEN ELSE statements and put the most common condition first. Break up formulas into multiple line items. If your formula includes more than 10 IF THEN calculations, think about using a LOOKUP. In some situations, you can also consider using a line item subset.
Formula Structure for Performance
Thinking Through Your Formulas
Manipulating Data with Line Item Subsets
Model Optimization Checklist
- Step 1 - Lists
- Does the list use Time as part of the key?
- Does the list use a combination of properties as a code?
- Does the list have a code?
- Does the list use Properties?
- Are there subsets on larger lists?
- Does the subset list follow proper naming conventions?
- Does the list include a top level when it is not necessary?
- Step 2 - Modules
- What dimensions are used in the module? Are they all necessary?
- What time dimensions are being used in the module? Can a Time Range be used?
- Are the dimensions in order?
- If there are any saved views, do they use the correct filtering?
- If there are saved views, are all of the line items in the view necessary?
- Is the default view clean?
- Step 3 - Line Items
- Which line items do not need a summary?
- Are text formatted line items overused?
- Are there more than 50 line items in a module?
- Are there excessive subsidiary views?
- Are there line items used as headers where the format is not set to No Data?
- Step 4 - Formulas
- Are there line items that can be placed in a systems module rather than within a calculation module?
- Are there any formulas that that combine text strings?
- Are there any formulas that are daisy chains?
- Are there long formulas, such as complex IF THEN ELSE statements?
- Is there an excessive use of the FINDITEM function?
- Are there SUM and LOOKUP combinations?
- Is the TEXTLIST function used?
- Do any formulas use the SELECT function, especially with time?
- Do any of the line items use conditional formatting with summaries turned on?
- Step 5 - Actions
- Are all the actions necessary?
- Do any of the actions result in errors when they are run?
- Check the data sources. Are some of them lists or modules?
- Check the data sources. Does each data source have an action associated with it?
- Step 6 - Time
- Is the main time scale of the model larger than it needs to be?
- Additional Resources
- Model Optimization Tracker