For insemination treatments there is no waiting list.
IVF treatments are spread such that the workload on the lab does not fluctuate greatly. This is very important to guarantee the quality of the work. This normally does not involve any extra waiting time for the patient.
For donor inseminations ther may be a a waiting list, depending on the availability of a suitable donor.
For IVF with donor egg cells the waiting list is (much) longer due to the lack of candidate egg donors. If you have a accepted kandidate for egg donation, the waiting period is shorter.