Making Succession Planning Measurable: Which Indicators Show That an Administration Is Prepared
Ask who could take over a leadership position if the head of department left tomorrow, and many public authorities answer with a name picked from gut feeling. A reliable figure is rarely part of the answer.
I see this situation regularly in advisory conversations: the question of who would succeed a key position is answered with a judgement based on experience, not on any survey. “Someone will manage it” is an honest answer, but not a robust one. It does not hold up in front of senior leadership or the staff council once the position actually becomes vacant and the presumed successor turns out to be unavailable for entirely different reasons.
Why a judgement is not enough
In many public authorities, succession planning is treated as a qualitative task: senior managers exchange informal views on who might be suited to which position, and these conversations rarely become binding. As long as no post becomes vacant in the short term, nobody notices that this produces no reliable overview. Only when retirement draws closer, or a resignation arrives unexpectedly, does it become clear whether the informal judgements actually hold.
The problem is not that senior managers misjudge their staff. The problem is that a judgement without a data basis cannot be checked, and therefore cannot be steered. An administration cannot tell how far it has actually got with succession planning if the only yardstick is the feeling of the respective manager. That is exactly why succession planning needs indicators, just like every other area of HR work.
A compact set of indicators
A large-scale survey is not required for this. From practical advisory work, a small set of indicators has proven useful that can be introduced without additional software and without a major data collection effort, because the underlying information already exists in most authorities, just not brought together in one place.
The first and most important indicator is the succession rate: the proportion of leadership positions for which at least one named successor option has been documented and agreed with the manager concerned. Documented here means explicitly more than merely mentioned: the person is identified, their suitability has been assessed, and there is an idea of what they would still need to learn before the handover. In my advisory experience, this rate tends to sit in the low double digits in authorities that have never dealt with the topic systematically, while organisations with established staff development reach noticeably higher figures.
The second indicator is the lead time to the age-related departure wave: how many leadership posts will become vacant through retirement in the coming three, five and ten years. This figure can be derived from the existing age structure without surveying anyone, and it sets the time frame within which the other indicators have to take effect.
The third indicator is the development readiness of the named succession options: how many of the documented successors are already considered ready to take over today, and for how many is a development period of one to three years still assumed? This distinction prevents a false sense of security: a name on a list is not yet readiness to take up the post.
The fourth indicator is the actual vacancy duration for comparable positions in the past, that is, how many months a leadership post remained unfilled on average before it could be filled again. This figure is usually already available in personnel records and shows very concretely what a lack of succession planning has actually cost in the past.
What these indicators achieve in practice
Once these four values are collected for the most important leadership positions and updated annually, something fundamental changes in steering. First, a vague concern turns into a concrete priority: an administration can see which positions will become vacant in the next three years while no successor is documented for them, and can act there specifically instead of trying to address everything at once.
Second, the success of staff development measures can for the first time be read off the succession rate itself. A mentoring programme or a potential assessment is successful when the number of documented, ready successors actually rises, not when many staff members have simply taken part in the measure.
Third, senior leadership gains an argument towards the finance department and the budget authority when early staff development or a transitional double-staffing arrangement needs to be justified. A lead time of three years until the next wave of retirements is a robust argument. A judgement based on gut feeling is not.
Fourth, the data collection forces an honest stocktake before a problem becomes acute. An administration that knows its succession rate and finds it at twenty per cent has a different starting position for its workforce planning than an administration that does not know this figure at all, yet believes itself to be safe.
Getting started does not require a major survey
An administration does not need to set up an extensive project for this step. It is enough to create a simple table for the twenty to thirty most important leadership positions: position, years until age-related departure, named successor option, development readiness. This table can be filled within a few weeks, because the information already exists with the respective managers. What matters is only that it is brought together and updated regularly, instead of remaining scattered across individual people’s heads.
Once these four figures have been collected, the discussion about succession planning typically changes. A recurring but inconsequential worry becomes an indicator that can be compared year on year, and against which it can be measured whether an administration is actually prepared, or only believes it is.