Any city has to give some thought to its ambition and brand in order to set sustainability goals.

IBM's long-standing mantra is 'Think.' What has always made IBM a fascinating and compelling place for me, is the passion of the company, and its people, to apply technology and scientific thinking to major societal issues.

And so when I moved to IBM, I moved because I thought I could apply technology. I didn't actually have to do my engineer - I was an electrical engineer, but I could apply it. And that was when I changed. And when I got there, though, I have to say, at the time, I really never felt there was a constraint about being a woman. I really did not.

One of the most important things for any leader is to never let anyone else define who you are. And you define who you are. I never think of myself as being a woman CEO of this company. I think of myself as a steward of a great institution.

Clients say, 'What's your strategy,' and I say, 'Ask me what I believe first.' That's a far more enduring answer.

I've been head of strategy at IBM and together with my colleagues built our five-year plan. My priorities are going to be to continue to execute on that.

The social network will be the new production line in a company.