Computation of alignment and calibration constants in CMS

The CMS detector is a very complex apparatus with more than 70 million data acquisition channels. The full physics potential of CMS and the recorded data can only be exploited with precise calibration and alignment constants that have to be produced in an efficient way. The CMS Collaboration has set up an infrastructure for alignment and calibration based on dedicated skimmed data streams providing inputs which are specific to the various workflows computing these constants. A prompt calibration concept allows for the determination of the most time-dependent constants almost immediately after the data are recorded, thus following as fast as possible any change in the running conditions. The paper will introduce the basic concepts of the CMS alignment and calibration infrastructure, and present results from selected workflows.