We expect our staff to work hard and to do their best.  But what is 'best'. I would contend it is something to do with always being aware of the company's mission, vision and values ands always acting in furtherance of the mission and vision whilst acting in accordance with company values ... and wherever and whenever possible doing so pro-actively off their own initiative.

This, of course, begs the question - do your employees know, and understand the company's mission and vision - and are they aware of the core values you expect?  If my 'definition, is right, and they do not know these things, they cannot be expected to do their best.  If they don't, it is your fault, not theirs.