Concatenation reduces the flexibility available to the mission planning system for scheduling of observations and risks distorting the allocation of nominal slew overheads to programmes. Additionally, experience has shown that the mission planning system is very good at scheduling observations, which are close on the sky, reasonably close in time. Thus, all proposers are reminded that concatenation must only be used when there is a very strong scientific requirement for the observations to be scheduled contiguously in time. This justification must be made explicitly in the proposal.
Current experience shows that the linked-observation facility is used very little.
Thus, consideration is being given to deleting it from the ISO system. Proposals requesting linking are discouraged.