To add a little to Shell Management's comments, you really cannot talk about "no blame" and "just culture" as though they are almost the same. They are totally different; one is discredited and the other works.
But the comment that the organisation must understand it is very valid. Not only understand, but be fully committed to forcing it to work, from the CEO downwards.
And that's where the problems normally start, with CEOs who neither understand or care about the actual operation of the business they run, and believe that "knowing how to run a business" in the same way that a management consultant "knows about business" is adequate.
The worst case is history of that was that idiot in charge of Railtrack when the Paddington crash happened. He regarded is as "obscene", to use his word, that he should be held responsible.