Thales Airborne Systems Research Articles

11.3.2 “Rework: models and metrics”: An Experience Report at Thales Airborne Systems

AbstractThis experience report illustrates the implementation of metrics about rework in Systems Engineering at Thales Airborne Systems. It explains how models and quantification of rework contribute to reduce this waste in development processes.This paper is based upon our real experiences. Therefore, it could be considered as an industrial contribution to share this method in Systems / Products Development and Engineering.This experience report describes an achieved example of metrics and its positive impacts on Defense & Aeronautics Systems. However, this document proposes a scientific way to implement our results in other companies. Clues are also given to apply this methodology through a Lean Engineering approach.Finally, Lean Enablers, key factors of success and upcoming steps are described to further improve the performance of Systems Engineering.

Sub-Reflectarrays Performances for Reconfigurable Coverages

A reconfigurable sub-reflectarray (RSRA) is studied to perform a realistic telecommunication scenario in Ku-band. The reflectarray panel is based on a proven technology with PIN diodes developed by Thales Airborne Systems and French Space Agency. This article presents different geometries of dual-reflector that can be used with this RSRA and the performances are compared, including quantization effects. It also presents that the main difficulty to tackle with RSRA is the alteration of the radiation patterns due to the specular radiation of the panel. Finally, two solutions to minimize this effect with RSRA are presented.

Time-indexed formulations for scheduling chains on a single machine: An application to airborne radars

Airborne radars are widely used to perform a large variety of tasks in an aircraft (searching, tracking, identifying targets, etc.) Such tasks play a crucial role for the aircraft and they are repeated in a “more or less” cyclic fashion. This defines a scheduling problem that impacts a lot on the quality of the radar output and on the overall safety of the aircraft. In our model, jointly defined with “Thales Airborne Systems”, the radar executes the schedule of the current time frame while the schedule of the next frame is computed. The radar is a single machine and a radar task is a job to be scheduled on the machine. A job consists of a chain of operations with identical processing times. The operations of the same job should be ideally scheduled with a given frequency, and any deviation from this frequency is penalized using a V-shape function. Our objective is then to minimize the total penalty. In this paper, we present three time-indexed formulations for the problem. Two of the formulations are compact and can be solved directly by a mixed-integer programming solver. The third formulation relies on a Branch-and-Price algorithm. Theoretical and experimental comparisons of the formulations are reported.

Automatic test generation: a use case driven approach

Use cases are believed to be a good basis for system testing. Yet, to automate the test generation process, there is a large gap to bridge between high-level use cases and concrete test cases. We propose a new approach for automating the generation of system test scenarios in the context of object-oriented embedded software, taking into account traceability problems between high-level views and concrete test case execution. Starting from a formalization of the requirements based on use cases extended with contracts, we automatically build a transition system from which we synthesize test cases. Our objective is to cover the system in terms of statement coverage with those generated tests: an empirical evaluation of our approach is given based on this objective and several case studies. We briefly discuss the experimental deployment of our approach in the field at Thales Airborne Systems.