A business rarely notices how much it knows until the person who knows it has gone. A retirement, a redundancy programme, an illness or a move to another employer can expose gaps that were hidden by years of competent work. Knowing how to preserve workplace knowledge is therefore not an administrative exercise. It is a matter of protecting judgement, relationships and hard-won understanding before they disappear.
The problem is especially acute in established organisations. A long-serving engineer may know why a particular machine must be started in a certain sequence. A sales manager may understand which overseas customer needs a formal approach and which values a personal telephone call. A public-sector officer may know where a policy will meet resistance, not because a manual says so, but because they have seen the same argument arise before.
Much of this knowledge was acquired slowly, through mistakes, observation and repeated contact with people. It cannot be replaced simply by giving a successor a password, an organisation chart and a folder of procedures.