I think it's true that how an organization approaches a safety management system develops over time. When you go from a prescriptive regime to a goal-oriented or safety management system regime, there's often a big challenge in that transition.
In terms of maturity, in 2000 I developed a thing called the safety culture maturity model, which was to describe that process. It was used as part of the previous railway act review. For your safety management system to work, it needs to be supported by a mature safety culture. As that process evolves, then your safety management system will become more effective.
At the bottom end of a safety culture, we have what we call a pathological culture where organizations don't care about safety. It's all about getting around the rules and not following them, and that, obviously, is not good for safety. When we get toward the top, the companies live their systems and go beyond any requirements and rules, and are very effective and safe. What's important is to see that, really, it's the maturity of the culture that underpins the effectiveness of your safety management systems.
Many times you can have two companies that on paper have the same management system but very different outcomes, and that's because of a poor underpinning culture. It's the maturity of the culture that is important rather than the maturity of the documentation of the system.