Control, assessent and removal of systematic effects in Planck

Planck is the most sensitive space mission to date dedicated to accurate measurements of the Cosmic Microwave Background. Its μK sensitivity calls for a comparable level of control of systematic effects, that represents the primary challenge to fully extract the wealth of scientific information encoded in the data. Planck has been designed and built to ensure, as much as possible, "in-hardware" rejection to spurious signals. Residual effects, however, need to be detected in the data and removed during data processing. In this talk we present a review of the main systematic effects in Planck, and of the design solutions adopted in the satellite and instruments to keep them under control. We then discuss the impact of the residual effects after data processing on the main scientific products.