Waiting times are gaps within your Driver's schedule. They occur when Tasks have set pickup and delivery time windows to prevent the Driver from arriving too early at the Task destination. They appear as yellow boxes between Tasks, with a specified waiting time interval.
How Waiting Time Works
Although similar in nature, waiting times are different from Breaks because breaks have a defined duration and interval, and must occur whenever specified in the Driver's schedule. Waiting times don't have a set duration, and users cannot influence them directly.
In the example above, we can notice that the delivery window on Task T-B6RQY9D5 is between 9 and 11 AM, while the delivery window for the Task right after it, T-075JHD1, is between 1:15 and 2:00 PM. Due to the strict time window delivery constraints imposed on both Tasks, Task T-075JHD1 can't start before 1:15 pm, hence why the waiting time is 2 hours and 7 minutes.
Essentially, waiting times represent gaps in your Driver's schedule and indicate that more Tasks could be delegated to the Driver to utilize their schedule fully. The waiting time also takes into account the travel time between two Tasks and it's deducted from the overall waiting time, as well as the setup and service duration.
Why waiting times may occur
There are several reasons why your routes may contain waiting times. These are the most common causes:
Strict Time Windows - For eLogii to be able to create a route where Drivers are not too early or too late to the Task location, waiting times may occur to avoid arriving outside of the designated time.
Lack of Tasks - Sometimes,if all your Tasks are optimized, and you still encounter large waiting times, this indicates that you could add more Tasks to your Drivers' routes, which would fill those gaps. To fix this instance of gaps, try extending the Task time windows so that eLogii can fit them together more closely.
Strict Time Windows and lack of Tasks - For cases where waiting times are longer, and realistically, a Task could be fit instead of a waiting time, usually there are no Tasks with adequate constraints that could be executed during that time.
Small Time Windows and Long Service Durations - If you notice long waiting times on a route, even when other Tasks nearby could be included, check whether those Tasks have extended service durations. For example, if there’s a two-hour wait and a nearby Task requires two hours of service, eLogii excluded it because adding the drive time plus the service time would exceed the two-hour window before the next Task. The best solution would be either to reduce the service duration or extend time windows so that the gap could be filled.
Small Time Windows and Small Break Intervals - This can commonly cause wait times to occur even for Tasks at the same location, especially if there are no other Tasks to fit before the break begins. In this instance, the start time is shifted to avoid any waiting time before the break. These seemingly illogical waiting times can be avoided by extending the break start interval so that Tasks can be completed one after another, and the break can start immediately after the Tasks are completed.
Removing and Reducing Waiting Times
While it is not possible to explicitly remove waiting times, as they are conditioned by time windows and how far apart they are (as explained in the example above), users can remove them or reduce them by trying the following:
Remove time windows altogether, or bring the time windows between Tasks closer. This will significantly improve the chances of reducing or completely removing waiting times between Tasks.
Assign more Tasks to your Driver to complete to fill the gap and remove waiting times that way. Additional Tasks can be assigned either through regular optimization or manual assignment to help fill in the gaps in the schedule.
Specify service and setup durations - in case you don't have defined service or setup duration times, adding them may help with removing or reducing waiting times and producing more precise results.
Reduce the Driver's speed factor and consequently reduce the waiting times, and in some instances, completely remove them. This takes into account that the Driver's vehicle is slower than the average, so eLogii will factor it in when calculating the travel time.
Add earliness and lateness tolerance if possible. While this does mean that Drivers can arrive earlier or later to Tasks than scheduled, these occurrences may reduce and sometimes even remove waiting times.