a medida que se necesite

= on demand, on request, as required

Ex. An automatic chasing system is provided for unfulfilled orders, but individual items may also be chased on demand.

Ex. The full query set is available for examination and experimental use on request.

Ex. Convenient, cheap and quick to reproduce, so that copies may be supplied as required for branches, other libraries and so on.

* * *

= on demand, on request, as required

Ex: An automatic chasing system is provided for unfulfilled orders, but individual items may also be chased on demand.

Ex: The full query set is available for examination and experimental use on request.

Ex: Convenient, cheap and quick to reproduce, so that copies may be supplied as required for branches, other libraries and so on.