If everything goes according to ___, work will be complete in December.

Time

Timing

Schedule

Lineup.

If everything goes according to schedule, work will be complete in December.

اگر سب کچھ شیڈول کے مطابق ہوا تو دسمبر میں کام مکمل ہو جائے گا۔

According to the schedule is a common and correct phrase that means things are happening as planned or on time.