> Your manager's job is to ensure you are productive.

The manager's priority should be organisational productivity; he's managing a team of people for the purpose of contributing to the greater organisation, not for the personal seclusion and self-fulfillment of each team member. Those are, sadly, secondary or tertiary goals.

If other people in the organisation can't be productive because he's blocking them from validly interrupting one of his reports then he needs to change.

"The needs of the many", and all that stuff. Sometimes the most productive days are those spent helping other people to be productive.

If supporting the wider org is part of the teams responsibilities, perhaps you will need to dedicate a first line person on a rotation to deal with incoming noise, to shield the rest of the team. It kind of sucks for the person in that role, but it's good for the rest of the team.

Of course, if your job is to be part of a responsive support org, you probably can't expect much seclusion at any time.

Which is great until u work in open plan environment which makes it impossible

Open plan env is a bad idea. Thanks to companies like Google using open plan, it's considered that you are lazy if you object to having an open plan.