But why do we consider this concept important? With KPIs, we can provide a holistic, real-time overview of the operations. However, it is necessary to enter more into detail and identify the root cause of irregularities in operations for specific situations.
A flight route with constant cancellations, a specific ground process repeatedly delayed, or aircraft downsizing. These are just a few examples that require situational details to implement corrective measures as soon as possible.
A Concept That Allows Analyzing, Monitoring And Tracking Flights In Detail
There are specific points in time or moments that are considered relevant during an entire flight leg development. These appropriate moments can be divided into particular sorts. They could be either milestones achieved or are actions that depend on multiple attributes to be completed.
To facilitate the analysis, we will call these milestones and actions, events, and processes. The events can be, therefore, defined as a business process relevant updates. Now the relevance can be determined by business rules according to the specific needs of each airline. This is entirely flexible and adaptable.
I will use a specific approach as an example of how a particular flight leg could be evaluated in real-time by specific defined events and processes.
First, we can identify the event category, for example. Events correspond to flight movements, and some processes correspond to the turnaround. Therefore, let’s say we have defined two main types:
- Movement Event
- Turnaround Process
Of course, this is just an example, and it can always be organized differently or add additional categories or sub-categories.
Assigning Events Or Processes To Categories
We can think of some specific events related to each of the categories mentioned above:
- Scheduled Departure Time
- Scheduled Arrival Time
- Estimated Departure Time
- Estimated Arrival Time
- Actual Departure Time
- Actual Arrival Time
- Aircraft assigned
- Aircraft changed
- Equipment assigned
- Equipment changed
- Gate assigned
- Gate changed
- Position assigned
- Position changed
- Additional Flight Leg
- Deboarding Begin
- Deboarding End
- Loading Begin
- Loading End
- Fueling Begin
- Fueling End
- Cleaning Begin
- Cleaning End
- Catering Begin
- Catering End
- Boarding Begin
- Boarding End
One crucial aspect before I continue, and as we mentioned in our blog post —3 Steps that will improve your airline’s turnaround process awareness— the point when the process is considered to begin, or end is entirely dependable for each airline.
Introducing Event Types — Essential For Flight Tracking
Now let’s say we consider some events more relevant than others as they have a higher impact on the operations and the passengers, for example, delays, cancellations, or any other irregularity. Therefore, it is possible to generate the following event types:
- Information: Events that occur under common standards, meaning, on-time.
- Warnings: Events that contain delays or might affect the regular operation, for example, delayed departures or delayed ground processes.
- Alerts: Events that require immediate attention or action from the airline, as it has a high impact on the operations and subsequently on the passengers, for example, cancellations or diversions.
To distribute the events and processes into the three types, we would require defined thresholds (e.g., 15 minutes departure delay) to identify from which point an event is considered information, a warning, or an alert.
To understand the business logic behind it, we can use the graph below, where I will use only eight events from the event list previously mentioned as an example.
Initial Flight Scheduling
As soon as a flight is scheduled, the scheduled times, STD and STA, are generated. Therefore, this event is considered as information.
Now let’s say closer to the flight operation date, the gate, initially assigned, changes. There are two options. The first one consists of a gate change before the day of ops or with enough time to not jeopardize the preparation of the aircraft. The second option implies the gate being changed within the minimum ground period.
This generates a warning as it can impact flight preparation and punctuality. Now during the flight preparation, there is involved the turnaround, which consists of different processes. As we can see in the example, cleaning, catering, and fueling also have two options. Either the processes begin and end on time or with a delay. When the processes are on-time, it is considered information; however, it is regarded as a warning if any of the processes are delayed. It again risks the flight departure to be on hold.
Looking At Departure Time
Now concerning the Actual Departure Time, there are also two options. If the flight leg departs on time, then the event is of type information. However, when the flight is delayed more than 15 minutes (industry standard), it’s considered a warning. There are several reasons for this. First, if a flight is delayed, it decreases customer satisfaction; it might require rebooking of passengers missing connecting flights or compensations in case of extreme delays, among others, finally, if a flight is canceled or diverted.
In both cases, as there is a severe impact on passengers and operations are, they are only of type alert. For example, suppose a flight is canceled. In that case, passengers must be rebooked at the earliest possible next flight or be provided with accommodation in case they have to remain overnight at the current location, and so on. On the other hand, if a diversion takes place, passengers won’t arrive at their original destination but will come to an alternative airport while the situation normalizes. This will, of course, cause misconnections, delays, flight re-accommodation that would require to be provided by the airline.
In other words, how airlines distribute their event types depends entirely on their needs and priorities; this is flexible. The different thresholds also variate according to each specific airline. In some cases, airlines even have multiple punctuality thresholds defined.
How To Trigger These Events And Processes In Real-Time?
An event, as described above, is expected to work with categorial meta information as the reason for eventing. As mentioned before, it contains types of data (info, warning, alert). In addition, it comes with supplementary information like delay minutes, changes reasons, or locations (for example, in case of a diversion, the new arrival airport).
Events have the nature of Big Data that ‘logs’ everything that happens, with the all needed data at that moment, structured by meta information. This is a very different approach compared to data flows that work mainly with the latest state data.
The concept is entirely rule-driven, and the rules can be defined by airlines using according to what they expect to see on the timeline. The purpose is to enrich your analytics data source, creating various events for each flight leg, enabling analytic measures to rely on more massive, more specific, and tailored data sets.
It’s Not Only About How To Enrich The Data But Also How To Visualize It.
After all the event definition and data processing, now we come to one of my favorite aspects, visualization. For this, we have developed a Timeline, which displays the story of a flight leg from flight planning to land. It shows events in real-time and in chronological order.
For the timeline visualized before, we can observe that the flight had been assigned a gate and a position since the previous day to departure. On the flight date, the runway and aircraft were assigned, catering and cleaning have finalized on time indicated by a green process bar, but on the other hand, boarding has completed with a delay of 5 minutes.
For this reason, the process bar is orange. Currently, the fueling and loading process is taking place, and we can see that while loading is running on time, fueling initiated with a delay of 55 minutes. Due to the delays in the turnaround process, the Estimated Departure Time (ETD) has been updated. Therefore, the latest event generated by the flight leg is an update in the Estimated Departure Time.
Coloring System & Icons for improved flight tracking
To understand the coloring system on the timeline, the following Matrix has been created based on status lights in a more general way. The status lights indicate punctuality and irregularity based on the following definition:
- Blue: An event with a schedule.
- Gray: An event scheduled for the future or an ongoing process.
- Green: An event that contains scheduled times or a process completed on time.
- Orange: An event with delay > 5 min, another warning, or process completed with delay > 5 min.
- Red: An event with delay ≥ 60 min, another alert, or a process completed with delay ≥ 60 min.
Additionally, the timeline consists of Icons that provide even further information on each event or process. Events appear on the timeline according to their timestamp. In addition, icons highlight special events such as milestones, time updates, and alerts.
Time Updates (ETD/ETA)
Flight Tracking Comparison
Additionally, we considered it relevant to analyze one single flight at a time and essential to have the possibility to evaluate multiple flight leg timelines simultaneously. Either the same flight number is operating on different dates or the same route other flight numbers. For example, when an airline has two or more flights a day to the same destination, The purpose of a timeline comparison is to identify frequent delays and irregularities that can be impacting the flight operations below a ‘comparison mode’ example.
With the support of a comparison mode example, you can visualize, for instance, if the flight leg always has a delay in one of the turnaround processes, or if the equipment is changed continuously, or if any irregular situation generally occurs for the same route or same flight number.
In other words, it is relevant to track the general operations KPIs and go into detail of each of the flight legs that are part of the operation to take action when warnings and alerts indicate something is causing issues in the regular procedures. The sooner and more detail your operation is evaluated, the easier it will be to make and implement corrective decisions.
What other events do you consider relevant for a specific flight leg?