"We've got to find some role models that are quite senior in the organisation who will start working in this way, so that more junior people will start seeing it as acceptable," said Grobler.
"There's still this perception that if you're not there full time, you're not serious about your career. So we've got past the HR model, the next one is looking for role models."
Angela Morrison, CIO of Direct Line Group, said that using technologies such as video conferencing and secure networks to enable flexible working is also an important tool in driving women beyond the middle management level.
"I have had some great middle management females working for me, but none of them wanted to step up. They said no, I'm very happy, because where I sit in the organisation I am in control of what I do. So when I want to go home I can just pack up and go home. If I go up one level I lose control," she said.
"We do need to drive woman beyond middle management. As a working society we need to address the way we operate."
Parmer added that the way job applications are written has a big influence on who applies for them. Men tend to apply for jobs if they have 50% of the skills, whereas women feel that they need a 90% skill match in order to apply.
By changing the language to make the job sound more accessible, more women are likely to apply, she said.
The European Commission published new figures at the World Economic Forum in Davos last week, showing an increase in the number of women on boards to 15.8%, up from 13.7% in January 2012. The boost comes after the European Commission introduced a 40% objective for women on boards based on merit in November.
"The proof is in the pudding: regulatory pressure works," said Vice-President Viviane Reding, the EU's Justice Commissioner. "Companies are finally starting to understand that if they want to remain competitive in an ageing society they cannot afford to ignore female talent."