<title>Operational concept of large telescopes</title>

Abstract

The singular way of scheduling at major observatories has favored certain types of astronomy. This has led to the discrimination of certain types of observations which could not be accommodated. It is the goal of future operations to open possibilities for some additional types of observational astronomy. Together with improved observatory operations the new observing modes can provide significant progress in the acquisition of astronomical data. Specifically, the capability to optimally match the schedule to observations should prove a major advantage of service observing. The VLT data flow project is designed to accommodate these new observing modes together with conventional observing. Simulations and first experience with the ESO NTT will prepare and refine the concepts and procedures foreseen for the VLT. The acceptance of service observing by the astronomical community is of critical importance for this new operational mode to succeed.