But effecting real change is far more difficult than simply adopting best practice.
"If you don't have diversity of thought we are screwed," says Doolan. "We may as well just run a lemonade stand if we are not willing to be challenged and change."
Despite all the efforts put in by Coca-Cola, for example, the job isn't done, says Rayner.
"I still see a lot of females who won't put their hand up until they are 120 per cent confident," she says. And when it comes to discussing the issue of sexual preference, the mere mention of the concept renders speechless some staff members, especially older white males.
The answer may lie at a far more basic level than policy. Individuals need to acknowledge and address the issue and, when making appointment and decision, organisations must be willing to take more risk in order to get a far wider mix of thought.
One fundamental problem, Doolan says, is that everyone has conscious and unconscious biases. Efforts to address these biases and overcome complacency towards diversity can be disappointing, even at the most progressive organisations, she says
"That has been the biggest challenge for me personally around adopting a true diversity agenda."
The next step, Doolan says, is recognising that each individual in the business and management team needs to address their own biases.
"I often think I have judged that person and it was wrong," she says. "That change of mind set is that individual starting point we can all bring to the diversity [question]."
EY isn't alone in that approach. Power says Westpac's staff members are going through compulsory unconscious bias training.
"[The training] is quite confronting," he says.
"You back yourself to do the right thing in a diversity and inclusion frame work. Once I had gone through the training I realised that as hard as I was trying, my mind set was still exhibiting a number of those unconscious bias tendencies."
Coca-Cola Amatil is well known for its diversity policies. Yet the company still has issues, Rayner says. Its current focus is on sexual preference, having gone a good way to "winning" other diversity battles already.
Driving diversity has moved on a lot since Rayner started her career under a group of women she called the "shoulder-pad brigade". Said women had fought their way to the top and they did everything they could, including throwing a chair on one occasion, to make Rayner tough.
It's a different era and Rayner tends to throw emotional intelligence and simple kindness at the problem instead of chairs. "I decided that [acting tough] wouldn't be my passion. I would make people more confident and give them a hand up."
Power adds that simple kindness can go a long way in business and have a positive effect on diversity. And he doesn't mean cocking your head on the side and saying: "I hear you." Managers can be genuinely kind, even if they have to make tough decisions.
One of the issues businesses such as EY and Westpac have found is that it's human nature to want to employ people like you. The opposite may be of more value to an organisation and taking risks can pay off.
That may mean looking beyond the obvious candidates who have been preening themselves for the job and consciously looking outside the box for staff.
When it comes to promotion, all too often senior management teams look just one level down for recruits, Power says, which perpetuates the lack of diversity.
"If you go below that level you can find tremendous talent and opportunity that has never had the opportunity to present itself."
