Question : MVP's: Is there a currently accepted standard for optimizing workbook calculations?

Does the discussion on the DecisionModels website (www.decisionmodels.com) represent the currently accepted thinking on Best Practices of workbook optimization for Excel 2007 or is it outdated?
 
I have a 75-page Management/Dashboard report, driven by a system download to a workbook data sheet with 20,000 rows x 105 columns. There are approx 90,000 sumif formulas in the workbook creating P&L’s and analytics and running graphs. Data sheet fields have Acct Tree levels, Dept Tree levels, concatenated columns of Account|Dept combinations, 2 yrs actuals, 1 yr budget and 1 yr forecast, etc

I want to understand the how design changes can optimize workbook performance, similar to how DBA's optimize system queries using a query plan. Without a tool to see calculation costs, my current approach to optimize the calculation flow would be to follow the framework discussed on the DecisionModels.com website

Steps I would take are:
1. sort the source data to shorten the lookup ranges and have the sumif formulas refrence a helper column that dynamically calculates the first/last instance of each lookup criteria to return smaller range addresses

But, I have questions on what strategies in the DecisionModels site will work for Excel 2007, such as
2. alphanumeric sorting of the worksheets by name, which according to DecisionModels worked in older versions of Excel
3. identifying and limiting Forward Calculations (formulas dependant on other formula results before they can calculate)
4. Pre-calculate interim values in helper columns to reduce the calculation load on the high-cost formulas
5. If you download the FastExcel sample workbook there are more strategies employed, some of which will take me some time to understand.

thanks in advance

Answer : MVP's: Is there a currently accepted standard for optimizing workbook calculations?

Maybe SUMIF isn't the best formula for your goal? with 90,000 in there it is worth investigating alternatives, such as DBSUM.
FastExcel will help you find the calc bottlenecks in your file. Well worth the investment if your file is too slow.