Importance of group dynamics: How to avoid coworkers throwing random unrelated work at you?

Thank you for the invitation and agree with the answer of colleague Omar.

Thanks 

That is depend on team leader, he -she has to determine the scope of responsibilities for everyone inside the team 

i think that group is a group that is done professionally, accurately and without errors, is the team that has been training well all the managing crises and risks

thanks for invitation

every one shall learn how to say NO at perfect time

Job description is the guide to solve these issues.  Every organization has to have one for each employee where we know our limits.