The departure of Paul Reid as Health Service Executive chief is a big surprise.

At this stage, he is just over three years in the post, which is not a long period of time.

But after the experience of Covid-19 for over two years and a devastating cyber attack, it probably feels much longer for him.

Mr Reid says he has no immediate career plans, wants to spend more time with his family and believes the HSE is entering a new phase.

He does not depart the HSE until December allowing time for a successor to be recruited.

During his tenure, Mr Reid has faced record hospital waiting lists, ongoing emergency department overcrowding and criticism that the Sláintecare health reforms are much too slow.

However, he has overseen a record health budget of over €21 billion a year, extra staff and a successful Covid-19 vaccination programme.

The pandemic experience brought him into conflict with Chief Medical Officer Dr Tony Holohan, who also leaves his post at the end of this month.

The Reid/Holohan clashes were essentially over calls from the CMO for the HSE to meet targets, like on testing and tracing for Covid, when the CMO was not responsible for day-to-day HSE operations or targets.

Mr Reid was the administrative public face of the health service, during the biggest health crisis in generations. Hospitals and health staff had never experienced anything like it.

He comes across as genial, but tough and very different to his predecessors.

Under questioning by the media and at Health committee hearings, he often gave general answers and could be very skilled at not being very specific.

Mr Reid was always protective of staff and his senior team when they came under public criticism.

He also had the advantage of having worked at senior level in the civil service, notably the Department of Public Expenditure and Reform and knows how government works.

Mr Reid's departure follows a series of other recent senior departures from the HSE and marks a massive change in top personnel and expertise for the health service.

That in itself will mean testing times ahead as the service has to steady itself administratively.

Whatever about the HSE entering a new phase, some of the longest standing health service challenges remain.