'Driving change in numerous organisations demands particular skills. We no longer spoke of what people needed to know, or what their qualifications might be, but of the qualities they had and how they approached their work'

We sat down on the grass and unpacked our picnic. Chit chat followed. The sun was hot and it was only April. She'd been off with a bad back. I'd been to the theatre. Her sister had left her job. Talk turned to changes in the NHS.

'Commissioning?' my friend asked, 'you mean contracts?' In part she was right, of course, and I struggled to recall a fuller definition. So I listed the tasks that commissioners face.

Commissioners understand local peoples' health and the differences in need between different communities, I explained. They set a vision about what is needed and talk to local people, healthcare professionals, managers and other commissioners (including local authorities) about their ideas. They find organisations who will provide services and make agreements with them. And they make sure what is delivered is good value; they are spending money on behalf of patients, after all.

Sometimes they commission really specialised staff (I reminded her of the plastic surgeon she met at a party who was a facial surgeon for babies). And sometimes they commission high volume, routine staff (I inquired how her grandmother had been since her hip replacement). And increasingly they commission services to keep people well - often in collaboration with local authorities. And just when they think they've completed all the tasks, the process starts again.

'Sounds like a big job, what kind of people do it?' She had never heard of anyone graduating from commissioning school. I asked her what she thought, as she worked in recruitment. We considered the kinds of people the NHS might need.

Public health folk were important, we agreed, they understood what illnesses people had and what the big killers were. And they understood how to get the best results for patients. They also knew how to prevent illness.

Geographers understood how ill health was distributed across towns and cities and they knew where best to locate services for greatest impact. Economists understood how to secure best value. Actuaries and analysts could process local information and make sense of it to inform priorities.

Lawyers were useful to ensure that contracts were used to best effect. And auditors and evaluators could check if the health of local people was increasing in the ways we had hoped.

People with experience of working in services were also valuable. They knew what it was to be at the sharp end of changes. They had weathered storms, and maintained services for patients. Their skill base was wide.

However, technical competence, though crucial, was clearly not enough. Driving change in numerous organisations demands particular skills. We no longer spoke of what people needed to know, or what their qualifications might be, but of the qualities they had and how they approached their work.

Good commissioners had qualities that were hard to measure. They showed leadership. They were skilled at working in a fast paced environment, and confident enough in their own abilities to make far reaching and creative decisions.

And they were able to convince others of their vision, while empathising with those colleagues facing changes. But they also knew when to assert their authority, instigate change and hold their nerve in the face of considerable resistance from colleagues and the public. They constantly challenged themselves and others about how best to deliver services. Above all, they kept calm and maintained clarity in the midst of chaos. They integrated technical skill with political savvy.

The challenges in nurturing an army of new commissioners was daunting. 'The ideal commissioner has it all,' my friend.said. 'You should write a column about it.' Lunch was over. And my head hurt.