Technical supervision is mandatory by law in Costa Rica: every project must have a CFIA-responsible professional for inspection and the site log. Its scope is verifying that works are executed per drawings and code.
Project management is optional but protects the business: it integrates scope, time, cost, quality, risk, communication, and stakeholders. It anticipates problems rather than reports them.
The difference shows in troubled projects: the supervisor documents what happened (which protects the client legally) but rarely prevents deviation. The director anticipates and proposes recovery plans. Most material projects need both roles, clearly separated.