Thanks for the replies merkhet and rayfinkle! I'm afraid I'm still not quite sure whether I'm doing something wrong or is it just the numbers. In the pdf Mr. Mauboussin says that for Wal-Mart he has 1 year ROIIC (for fiscal 2014) of -2%, 2% for rolling 3-year period and 21% for rolling 5-year period. I took the numbers (although I can't for example exactly match his average invested capital of USD 145.8 billion for Wal-Mart in fiscal 2014 (I get 141 billion) or the NOPAT for same year (his 18.8b vs. my 18b), anyone has an idea how he gets those 145.8b and 18.8b?

Anyway, here's how I'm trying to do it now. 1 year ROIIC: (FY2014 NOPAT - FY2013 NOPAT) / (FY2013 IC - FY2012 IC). That's exactly like he proposes so I assume that's the correct formula?

So is it correct then that to get a 5-year rolling ROIIC I need to calculate first 1 year ROIIC for 5 years, with the last one being in this case = (FY2010 NOPAT - FY2009 NOPAT) / (FY2009 IC - FY2008 IC). Then I have 5 ROIICs and simply calculate the 5-year rolling number as the sum of those 5 ROIICs divided by 5?

Without managing to know how Mauboussin exactly calculates his (average) invested capital and NOPAT (this one I especially struggle understanding how it can be so different from what I get..) it's impossible to arrive at his example ROIICs for Wal-Mart and that way see whether I'm doing something wrong. Thus asking for help here.