Who will succeed David Cameron as Conservative leader, Sir Alex Ferguson as Manchester United manager or - to take a name almost at random - Professor Les Ebdon as the Director of the Office of Fair Access to Universities? Nobody expects any one of that trio to step down from their current post any time soon. Yet sometimes events conspire to create a wholly unexpected senior level vacancy. You never know what is lurking round the corner. And organisations that do not plan for the succession as part of their overall business planning, are taking a huge risk
Yet, just as so many people are reluctant to make a will out of a superstitious dread of looking too far into the future, all too often business managers fail to prepare adequately for succession. It can be a costly mistake. But of course, succession planning is easier said than done, despite the fact that a cursory internet search reveals plenty of templates intended to simplify the task.
Because succession can become necessary all of a sudden and in unforeseen ways, a rigid approach may not be good enough. A succession plan that does not allow for a degree of sensible flexibility may fail to cater for what actually happens, rather than what was predicted to happen. There is a lot to be said for a principles-based approach, which reflects the values of the organisation as they are at present, and as they are expected to develop, and also the way the business and its marketplace, is expected to evolve in future.
Often there is a strong temptation to look only at internal candidates for promotion when it comes to considering succession. This is understandable, but there can be a danger in making assumptions. Simply to assume that a good "number two" will become a good "number one" is over-optimistic. Many managers who are highly effective side-kicks lack the vision and drive necessary in a truly successful leader.
Having a high level of skills is not in itself a guarantee that promotion will result in success. When Tony Blair was Labour leader, Gordon Brown was a widely respected "number two", and there was a widespread assumption - quite apart from whatever the two men were supposed to have agreed - that he was the ideal successor. As a result, when Blair stood down, Brown received a "coronation" - but never managed to win a single election, after his predecessor had won three. In the same way, David Miliband seemed to many to be a credible successor to Brown, but perhaps wavered once too often, and in the end lost out to his brother. Whatever criticisms some may make of Ed Miliband, in pursuing the top job he showed a level of single-mindedness that is one of the attributes of an effective leader.
But in planning succession, one needs to look at a range of attributes. A long-serving "number two" may not have the future vision to take an organisation on if it takes too many years for him to reach the top of the tree. There may be greater energy and potential in more junior people.
Another key issue is - what happens to those who are succeeded? When a leader steps down, there is a risk that his or her skills and experience may be lost to a business. This is usually a dreadful waste. The mere fact one is no longer "top dog" does not mean one has no value. A change of role and status can be energising both for the individual and the wider team.
So it is vital for those in top jobs to buy in to the concept of succession planning, and to recognise that looking to the future may offer genuine - and exciting - opportunities not just for those who take up the baton and for the organisation as a whole, but also for themselves.