What do Marissa Mayer, Angela Ahrendts, Mairead Lavery and Janet McCollum all have in common?

You’re probably familiar with Mayer, Yahoo’s chief executive and Ahrendts, Apple’s senior VP of retail and online stores, but less so with Lavery and McCollum. But all four are perfect examples of successful business leaders in their respective fields.

The fact they are all women is irrelevant – or is it in 2014? Northern Ireland-born Lavery and McCollum are among the top-achieving female bosses of their generation.

Montreal-based Lavery is vice-president of finance at Bombardier Aerospace with responsibility for all the accounting, reporting, treasury and finance functions for the Canadian group which reported revenues last year of more than $18.2 billion.

According to Lavery, she has never once considered a "glass ceiling" could hold her back. She began her career in Short Brothers, the Northern Ireland subsidiary of Bombardier, as manager of financial reporting.

McCollum, for her part, is effectively the highest-ranking local female boss – as the chief executive of Moy Park, the biggest private sector business, she is technically in charge of its parent company Marfrig's annual £1.5 billion European operations and its 11,500 employees.

But, according to Women In Business NI, a 1,000-member networking organisation, her success is not reflective of how business operates locally. Its research shows only five of the top 100 companies in the North are led by women.

Roseann Kelly from WIBNI believes this figure should be closer to 30 per cent and she says evidence proves a diverse workforce equals a more productive workforce. The organisation has been running a campaign to get at least 30 of the top 100 local companies to sign up to its gender diversity in the workforce campaign. It will reveal how well it has succeeded at its International Business Women's Conference, which gets under way today in Belfast.

The three-day conference will feature entrepreneurs and business leaders from across the globe, the aim being not only to inspire Northern Ireland-born businesswomen, but to highlight the business case for diversity at work.

Mairead Lavery, one of the conference speakers, says she especially wants to get across her belief that perception is reality when it comes to succeeding in any walk of life.

“Sometimes the biggest challenge can be in our own mindset. It is not about whether we can do it, it is about whether we think we can do it.

“We need to see more women on boards and in leadership roles and, to achieve that, we need to create pipelines for women to succeed, particularly in certain areas such as engineering for example.”.

Discrimination trap
Julie Meyer, a London-based American who grew up in Silicon Valley and is the founder of Ariadne Capital, also believes that businesswomen cannot be successful if they subscribe to the concept of glass ceilings. Meyer, the keynote speaker today, has this advice for female business executives: "Don't look for discrimination. If someone treats you differently, don't focus on it because you are woman. If one door closes for me, I look for the next opening; I never focus on negatives.

“It is also my belief that the world is becoming more feminine . . . What was perceived as traditional female skills, such as empathy and emotional intelligence, are more valued today and its these feminine leadership characteristics which are helping both men and women in business.”