How to Train Staff for Critical Thinking

Ok here I think is a good topic, one which is seldom written in the textbooks.

Question: How do you train staffs on critical thinking?

By critical thinking I mean doing away with I see therefore I copy mentality.
By critical thinking I mean not just accepting a number or a statement as a fact because it was given by someone else. By critical thinking I mean understanding first the assumptions before using and re-using formula or an equation. Can that be taught? Looking forward to your comments.

Note: There are obviously two concerns here. One is the skill (which I want to focus on), and the other one is the will (I dont want to think, I rather be spoon-fed). Which case do you encounter more?

I struggle with this as well. I need test engineers that can think critically about ways to challenge systems and am finding it increasingly difficult to find people who have developed this skill. I think it takes both an innate ability and continuous exercise (and, as you note, will).

We go through a few exercises to help get folks moving along this path. The first is to show them a date field on a computer application and then ask them to come up with different ways to challenge the data entry. For example, 8/4/17 in the US is August 4; whereas in the EU, it's April 8. I hope to elicit thinking that creates challenges like this as well as 8-4-17, 4-Aug-17, dropping segments of the date field, entering dates that don't exist (31-Feb), etc. Once they do get thinking along these lines, they either start carrying the torch (innate ability) or they bog down, unable to come up with anything.

The Theory of Constraints (TOC) has a huge focus on critical thinking which revolves around challenging assumptions. They have developed many tools that teach people to think critically. TOC was 'created' by a physicist and critical thinking is, in my opinion, one of the main pillars of the entire theory.

At first, the thinking processes (TP) can seem overwhelming, but with guided practice and use, it becomes easier to the point that you can do it in your head.

These tools range from a current-reality tree (identify the problem and the root cause), future-reality tree (where you want to be after solving the root cause), and a strategy-and-tactics tree (how to get from where you are to where you want to be), to name a few.

I highly recommend doing some research into this. It was 'created' by Dr. Eli Goldratt. If you have no prior knowledge as to what TOC is, start with reading the book called "The Goal" by Dr. Goldratt.