The SUMIFS function works in a similar way with text as with numbers, but there are two key differences. First, text in Excel ...

It’s not about a single fix or one-time initiative, but about embedding learning into the DNA of how public systems operate.

Twenty years after the introduction of the theory, we revisit what it does—and doesn’t—explain. by Clayton M. Christensen, Michael E. Raynor and Rory McDonald Please enjoy this HBR Classic. Clayton M.