title: SUMIFS on a range of data
body: <p>I currently have this formula in Excel:</p>
  
  <pre><code>=SUMPRODUCT(SUMIFS('OPPORTUNITY LIST Current Month'!$W:$W,'OPPORTUNITY LIST Current Month'!$J:$J,"Open",'OPPORTUNITY LIST Current Month'!$A:$A,'Opportunity Allocation'!$A:$A))
  </code></pre>
  
  <p><code>'Opportunity allocation'</code> is a sheet with the unique identifier allocated by name in a column, so for this person column A of <code>'Opportunity allocation'</code> has all the unique identifiers of their lines of data in the <code>'OPPORTUNITY LIST current month'</code> sheet. </p>
  
  <p>This formula works and returns sum of column <code>W</code> for all of the rows matching identifiers allocated to the person.</p>
  
  <p>The problem is it basically crashes Excel when I run it, taking 20+ minutes to run just on one cell which is obviously making it a nightmare as I need to do this for ten different values across a team of thirty people! </p>
  
  <p>Can anyone help me write this in a more efficient way?<br>
  I assume <code>SUMPRODUCT</code> is what's causing my problems?</p>