IBM at one time had “Think” as its slogan. One of the greatest difficulties for employers is the lack of critical thinking ability and dispositions among their employees. Employees can be better and happier when they are encouraged to follow the RRA strategy, which are basic guides to critical thinking: Reflect Seek and give Reasons Seek and compare Alternatives.
Employers can develop training programs to promote critical thinking skills and dispositions. You might follow some or all of the suggestions (adapting them for your situation) in “Twenty One Strategies and Tactics for Teaching Critical Thinking“. A super-streamlined version of the definition/conception of critical thinking, which is the goal for these strategies and tactics, would be worth reading to make sure we have similar goals. It might well also be disseminated among your employees. “Critical Thinking: A Streamlined Conception” is a more detailed definition/conception of critical thinking–with examples. See the rest of the “super-streamlined” page for even more details and depth, if you seek more. If you seek a test, you might look at “Testing for Critical Thinking“.
No claim is made that critical thinking is by itself enough to make a good employee. But it helps a great deal.