Concurrent access to a task assigned to a group of users

Hi there,

I would like to know a task can be assigned to a group of users. However, I have tried the following but it seems to me that there's no control on restricting only one of the users (within the group) can modify the content of the task at the same time, am I correct? 

For example, I have a task being assigned to user group with 2 users, namely User1 and User2.

The task will be appeared in the inbox of both User1 and User2. 

(i) User1 opens the task and then specifies details of the associated Form (without clicking the 'Save as Draft' or 'Complete' button).

(ii) User2 opens the same task and then specifies details of the associated Form. Then click 'Save as Draft' button.

(iii) User1 finishes his update and click the 'Save as Draft' button.

(iv) User2 re-opens the task and finds that his update was over-written by User1.

Is this work as design?

If I would like to implement certain locking mechanism to ensure that step (ii) above will not be allowed to save because it is being modified by User1 (i.e. step (i)), any advice on how it can be implemented? 

Thanks in advance.

Best regards,

Thomas