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Key features

AirTOp WIZer (What-If AnalyZer) is a COTS (Commercial Off-The-Shelf) computer application which makes use of the AirTOp fast-time simulation engine to produce detailed, up-to-the-minute forecasts of air traffic demand, traffic complexity, and controller workload.

These forecasts can be used to provide decision support to supervisors and FMPs, by providing warnings when the entry count, occupancy or workload/complexity of a sector is forecast to exceed some user-defined threshold.

The tool provides further decision support by proposing ATFCM measures to balance demand and capacity, and allowing the user to produce “what-if” scenarios which present the results of such proposed measures by the system or by the user.

As illustrated in Figure 1, WIZer takes in input data in the form of flight progress messages (EFD, OLDI, …), radar tracks (CAT62, …), wind and storm forecasts, the current sector opening scheme and the current activated scenarios or regulation.

The forecast data are displayed to the user in a graphical interface (charts, table, 2D and 3D views, …) which highlights periods during which the demand is forecast to exceed capacity. The tool provides options to either reduce demand or increase capacity, and displays the results of executing such measures on the updated forecast, allowing the user to perform an interactive what-if analysis of the available options.

WIZer functional architecture

The forecast simulation has a time resolution that can be set down to one second, and runs from the present time to anything from 1 to any hours ahead, as selected by the user.

Aircraft movements are calculated based on the performance characteristics built in to the model, which may be based on BADA or on the client’s own performance model. These movements can be constrained by letters of agreement built in to the operational model. Free Route Airspaces (FRAs) modelling is also supported.

WIZer can model the full operational environment of any ACC or group of ACCs. It provides complexity and controller workload measurements for all types of sector (e.g. en-route sectors, TMAs, etc), or for tower controllers, and provides ways to manage this complexity and workload.

The workload and complexity model is specified using a GUI within the WIZer application which allows the WIZer administrator to modify, parameterise or customise the model.

Within an ACC, sectors can be organised into groups and sub-groups (sector families), for example to take account of different ATCO licensing requirements in different groups of sectors.

Import and definition of the operating environment data is done using graphical tools within the WIZer application, as part of the initial installation of the tool. When the operating environment changes, for example due to a new AIRAC cycle, WIZer switches automatically to the new environment at the appropriate time without interruption of services, assuming that the relevant data is provided ahead of time.

WIZer is designed as an expandable, modular application which can be easily customised to fit clients’ specific needs. In particular, new modules can be added to the application without modifying the system architecture in order to support the following:

  • Different data sources
  • Different workload/complexity calculations
  • New traffic counts
  • New systems of sector and airspace organisation

Input Data Processing

Interfaces and Data Links

The AirTOp WIZer software is able to acquire input data and transmit output data via multiple interfaces:

  • local file system
  • remote directory sharing protocols: Samba, NFS
  • network procotols: TCP, UDP
  • web services: NMOC B2B

The WIZer architecture enables additional Data Links to be easily integrated by Airtopsoft, such as a local flight data processing system, or custom flight CPR messages.

Flight Progress messages

  • ADEXP Air Traffic data
  • EFD Flight Plan Progress
  • NM B2B Flight and Flow [V4]
  • Stanly ACDM
  • OLDI [V4]
  • FIXM [V4]

Importers of custom format can be implemented by Airtopsoft on demand.

Aircraft Tracks / CPR messages

  • Asterix CAT062
  • Asterix CAT011
  • CPR messages

Weather information

  • Current Weather Condition:
    • BUFR
    • HDF5
    • Custom
  • Forecast Wind:
    • GRIB
    • GRIB2
    • Custom
  • Forecast Bad Weather:
    • GRIB/GRIB2
    • WXXM [V4]
    • RadTRAM (DLR nowcast)
    • NowCastMIX (DWD)
    • Custom

Human Resources (HR) and rostering plans

The WIZer systems supports the connection / data exchange with local HR / rostering plan management tools:

  • Stanly TEP (DFS)
  • Gasel opening scheme
  • Custom

Military airspace activation plans

The WIZer system supports the acquisition of Military airspace activation plans from the following sources / formats:

    • LARA [REF_007] [V4]
    • DFS Stanly ACOS)
  • Network Manager B2B [V4]
  • Custom


User Access Management

WIZer ACC allows distinguishing between different users, granting them different access and management rights to the tool. In addition to the default users (Administrator, technical, operational, viewer), other new users can be created and their rights configured as needed.


The system is able to produce reports and documents in the following formats: images (PNG, JPEG), text files and PDF files. Some documents are created automatically by WIZer, others can be explicitly requested by the user.

Archive and Replay

The system includes one or several machines especially dedicated to data archiving. The archives can be accessed from a dedicated interface.

The Replay feature of WIZer allows the user to fully restore and reproduce the state of the system at a specific past point in time, playing back the reception of all received and archived input data. The Replay feature is operated from a player, similarly to the one within AirTOp. It is a key element of WIZer’s testing environment.

A specific simulation data archive is recorded from flight plan progress data. This independent data can be used in AirTOp even without WIZer module and allows for post-ops analysis.


WIZer ACC is provided with an End-user Manual, Advanced User Manual and Installation Guide.

System Monitoring and Control

The system also includes a Monitoring and Control HMI which gives an authorized user access to modify system configuration parameters, status reporting, download of log activity files and display of user access activity. Furthermore, the HMI can display asynchronous notifications emitted from the server which can be informative notifications or alerts.

Performance, RAM (Reliability, Availability, Maintainability)

Some performance values of WIZer:

  • Number of pre-defined scenarios: limited only by disk space
  • Changing a scenario: < 60s
  • Number of pre-defined sector configurations: 2500+
  • Simulatenously simulated flights: 5000+
  • Computation of workload and complexity values: < 60s
  • Number of controller working positions (20+)

AirTOp model has proven to provide reliable and accurate enough results as a result of more than 3 years working on a proof of concept and later on full operational testing in a large ACC (Munich). AirTOp WIZer ACC software can run 24h a day, 7 days a week, with an Availability above 99.9%. Some Reliability and Availability is provided by various auto-correction, auto-recovery and calibration functionalities integrated into the system.


WIZer contains a specific testing environment which allows for the system to be tested, validated, and calibrated for operational use. A collection of unit tests is included in the testing environment. Non-regression tests are based on the replay feature and on the profiling traces generated by the system when started in Test Mode and provide information about model validation, forecast quality, global performance of the software components on the background side as well as graphical performance of the WIZer Client. Additional procedures for manual testing are also part of the non-regression tests in order to test and stress the HMI of the WIZer Client.

Software Quality Assurance and Quality Control

As a result of a long history of maintaining more than 50 AirTOp deployment licenses, Airtopsoft has implemented a vast quality control management system which is ISO 9001 certified.

Specific high-quality software development practices are applied and documented in internal Airtopsoft Development Guide. Industry standard tools are used for version control as well as build management and continuous integration.

To meet the business and technical requirements that have guided AirTOp design and development, extensive Software Testing is carried out. This includes unit tests and standard scenario based tests.

Bug reports, enhancement requests and subsequent interactions are managed by a custom Admin tool which is designed and developed internally specifically to respond efficiently to customer needs.