Venus Express (VEX) is the first dedicated mission to Venus in over a decade. It lifted off from Baikonur on a Soyuz-Fregat launcher on 9 November 2005, arriving at Venus on 11 April 2006. Since arrival, its suite of instruments has been collecting data on the atmosphere, surface and magnetosphere from a 24-hour period polar orbit. The Venus Express Science Operations Center (VSOC), located at the European Space Astronomy Center (ESAC), Madrid, coordinates and consolidates all science requests from the instrument teams, fulfilling the science goals established by the teams and the project scientist. VSOC generates accordingly conflict-free pointing timeline and instrument commands to be uploaded to the spacecraft for execution onboard. Here we will present how science requests from individual science teams are consolidated and prioritized in the VEX planning cycle. We will discuss how the VEX seasons drive the selection of priority observations. We will review the main resource constraints on the SC and Venus environment that affect the selection, and how the observation requests are traded-off in case of conflicts. We will finally show how this process has evolved in time as the mission approaches its last phase of operations.