From Jacqueline Lichtenberg, June 2013: It is important to time a transfer exactly so that the next transfer assignment will be "in step" with the next assigned Donor. The matrix pattern of timed transfers goes Tecton wide and keeps channels and Donors of compatible speed and capacity in step with one another. One accidental miss can strain the schedules for hundreds when there is no slack in the staff.
Gens produce selyn at a variable rate, depending on exposure to Simes in Need, but each Gen has a personal maximum rate of production. The production cycle usually matches the Sime's consumption cycle, putting the Gen back where he/she started before the previous transfer at about 28 days.
For most Gens, Donors and Companions included, selyn production tapers off after 28 days, and the body produces only as much selyn as is used for life functions (practically nil for Gens compared to their production rate) or lost to dissipation into the air. In other words, Gens reach a steady-state after about 28 days.
Some Gens who are talented Donors or Companions will spike selyn production even after reaching that steady state upon exposure to a channel in Need.
Channels, like all Simes, use up selyn at a variable rate, depending on the demands of metabolism, and on augmentation episodes -- times when the Sime deliberately increasing selyn consumption rate to augment muscle strength, or to move faster in Hunting Mode. Freeband Raiders deliberately waste selyn in order to enjoy an early Kill. Civilized juncts often consider augmentation a necessity of health. Illness and other conditions can consume selyn at different rates.
The Tecton attempts to regiment behavior so that transfers can be scheduled exactly. For Donors to reach maximum selyn storage at the time their assigned channel is at optimum Need for a good transfer is to be "In Step." Once established in step, the pair will stay in step through the following month.
It is very relaxing and reassuring to a Sime to be accompanied through the month by a Gen who is in step.