Proper maintenance, performed in a timely fashion, can guard against simple problems that left unattended could dramatically shorten the life expectancy of the roof.
Alternatively, the low areas of the roof can be built up and the flow of water redirected to existing drains, scuppers or roof edges. A side problem from ponded water can be plant or vegetation growth. Roots from vegetation can be very damaging to the membrane when allowed to grow. When left unattended too long, the solution is a total repair or replacement of the affected area(s).