Looking for simple way for open/close budget action

Hello,

Our Planning version is 11.1.2.1

Our organization could be descibed as follows :

Entity 'Total'

    Entity '01'

        Entities '01.xx'

    Entity '02'

        Entities '02.xx'

Entities '01' et '02' are two differents departments, with specific users.

During the budget build, all data are currently agregated in the 'Total' entity.

Example of scenario :

In final phase, I have to freeze one departement, for instance '01'.

The users of the '02' department continue.

As EPM admninistrator, I do that with a very basic and efficient way, with the security on the used version (Read or Write), applied directly with