[SOLVED] Responsible?

I have an acitivity Y from 05/02/2016 to 05/05/2016 assigned to the user a, b, c. User a is assigned 2 date, user b is assigned 1 date , user c is assigned 1 date, User a is responsible person. I want to ask about entering results into real work allocation.
As far as the configuration of the persons responsible activitty is the result of that user entered. Thus, only the user a entered result of activity, so how to enter results into the activities of 3 users in real allocation work? How to enter the results of a group of people.
Thanks for help!

Sees the responsible like a person that ensure execution of works.
For instance, you can define a responsible to a delivery.
A responsible receives emails and alerts.
When required it can enter a result (comment) on the element.

Don't mix with a comment entered to a task in a timesheet.

I understand responsible, I mean in the above example, user a, who is responsible for the enter result is of course. But user b and user c are not the person responsible,so how enter their results on the real work allocation? And how to enter results for a group of people instead of just entering the results of the user a, in the example above activities are assigned to 3 users( And I configured only for the person responsible in the activities are entered results).

First things first!
Why others users must enter a result?
Explain to me, what do you want the software to do for you.

I mean,activity is assigned to 3 users, 3 users must turn enter their results.