Execute a winning strategy for results

After a leadership team thoughtfully sets a new direction, why are the results envisioned not being realized? Formulating a winning strategy takes great minds and effort and, when it doesn't yield expected results, it is disappointing to say the least.  

I believe the first insight to getting results lies in the fact that executing strategy is complicated.  I didn't use the word 'complex' which implies an intellectual challenge.  Being complicated acknowledges that there are many factors that on their own are simple in nature, but the interplay among factors makes it a complicated maze to navigate.