Protect your Excel investment

 You spend months to develop a financial model on Excel and it finally worked.  You passed it to your users.  But a few weeks later, your users called you and complained the model not longer worked.  Of course, they said they didn’t change anything.  You took a few days to investigate and discovered someone changed a formula.  The rest is history!

http://algconsultings.wordpress.com/2011/01/04/protect-your-excel-investment/

How do you protect your Excel investment?