Time Constraints: The Cost of Sustainability - Sustainable Urban Logistics: Concepts, Methods and Information Systems - page 172

Fig. 9 Readjustment of a group of customers located inside the restricted zone (PRZ) to visit
them after the time window is open again
This operation, depending on the number of customers rearranged, might cause
the last ones of them (up to customer i ? 1) to be assigned arrival times after the
end of the day tf. In that case, the route will be completed only with the customers
that can be visited inside the time horizon, leaving the rest of them to be incor-
porated in the next vehicle's route.
The visit to the reference customer will also have to be moved back, together
with the customers visited before it, in order to reduce the overall route time.
In this process, if the customer visited before the reference one is located inside
the restricted zone (see Fig. 10 ), the visit time to all the customers, including also
the depot, must be moved back until t P ref D f ¼ t VC . On the other hand, if
before the reference customer the vehicle has to visit other customers located
outside the restricted zone, they can all be moved back as far as possible, keeping
outside the closed time window period only those located inside the restricted zone
(see Fig. 11 ).
Fig. 10 Readjustment of the reference customer when it is preceded by another customer located
inside the restricted zone