Suppose a person required to attend Friday prayer begins traveling to the mosque but is forcibly carried elsewhere before the congregation takes place. The initial journey has not secured the required attendance.
If attendance remains required and possible, a renewed effort to reach the prayer is needed. This is not because each movement in the first journey was an independent obligation; the means failed to achieve its purpose.
Principle: performing a means once does not invariably complete the related duty. One must ask whether the intended objective has been reached or still requires action.