Greetings Hossam,
I am assuming that you have created Maintenance Plans with Scheduling Period of ~1 YR, and you have scheduled them in IP10, but you do not regularly run IP10 manually, nor IP30 with the "Rescheduling" indicator set. I infer that it is enough if you did any of those, for instance running IP30 extends the schedule from today for the length of the Scheduling Period, and so the new schedule will be created for you.
Please let us know if this is the case. Also, you mention the "new preventive maintenance plan has to be presented" - do you mean the schedule (as in IP19), or the actual called Orders?