A plan that names successors against today's roles is preparing for the organisation the company is leaving, not the one it is building.
Why it matters when the plan changes
Most succession plans are built from the current organisation chart, because that is what exists to build from. Governance codes treat succession as a continuing responsibility alongside board composition and evaluation, which assumes the roles under review stay stable. When the strategy changes, the roles change with it, and a plan carefully prepared against the old shape becomes a list of well-developed people matched to positions the plan no longer needs in that form.
The tension is between depth and breadth. Developing a small number of identified successors is efficient and concentrates risk on the few; developing broadly is expensive and dilutes the attention that makes development work. Replacement planning avoids this tension by naming substitutes rather than building capability, which is cheaper but leaves nothing developed. Neither depth nor breadth resolves without a view of which roles the current plan actually depends on.
In practice
A group maintains two named successors for every executive role, reviewed annually. A new operating model merges two functions and creates a third that did not previously exist. The succession work is current, thorough and about a structure that no longer exists, and the new role has nobody prepared for it.
Evidence
Succession planning is defined as an ongoing process of identifying and developing potential leaders rather than filling a vacancy when it occurs.
Succession planning, Wikipedia (2026)Governance codes place composition, succession and evaluation together as a continuing board responsibility.
Financial Reporting Council, UK Corporate Governance Code (2024)
What it cannot tell you
Succession planning tells you whether people are being developed against a defined set of roles; it cannot tell you whether those roles will still exist in that form. It is silent on strategy change, and a plan can be executed well while resting entirely on an organisational chart that is about to be redrawn.
Questions
Replacement planning names who would step in tomorrow. Succession planning develops capability over time so that more than one credible answer exists when the question arrives. The first is a list and the second is work, and organisations routinely maintain the list and skip the work.
Against the plan, then mapped to roles. Roles are the more stable-looking object and the less reliable one, because a strategy change rewrites what a title actually demands without changing the title. Building against the chart quietly assumes the current structure survives.
Whenever the plan changes what the leadership roles have to do, which is more often than an annual cycle. The UK Corporate Governance Code, updated by the Financial Reporting Council in 2024, treats succession as a continuing responsibility rather than a fixed annual exercise, alongside composition and evaluation.
Evidence that they can carry what the role will demand under the pressure the plan creates, not seniority or time served. Readiness is a statement about how well someone matches a specific future demand, which means it has to be reassessed when the demand changes rather than accumulated.
A thorough plan against a structure that is about to change. Wikipedia's 2026 entry on succession planning describes it as ongoing identification and development rather than a one-off replacement exercise, yet plans are still measured against a fixed chart. The failure lies in that mismatch, not in execution.