Scheduling on the edge of turbulence

Recognizing different work-center calendars in shop-floor-control scheduling has a number of unexpected results. For instance, routings can no longer be assigned a fixed length, nor are the results of forward versus backward scheduling always equal. Small changes in initial schedule dates can cause drastic and unpredictable changes in the answers provided by scheduling; this turbulence limits the ‘resolving power’ of simple scheduling, and may destroy entirely the usefulness of more complicated planning systems.