I have used this tool, with some modern-day modifications, for years. When I was a safety manager of a facility I would constantly be looking for these indicators as a means to validate what I was “feeling”. As safety pros, we have a sixth sense of how things are going, but there are so many markers/indicators in measuring safety cultures that having a list like this comes in handy.
I have also used this in some workshops with my management teams so they can come to their own conclusions as to what phase the plant is in. These workshops are invaluable at allowing management to recognize they are somewhere they had not envisioned!