Basic research in the so-called Giotto project at the University of California, Berkeley resulted in the Logical Execution Time (LET) abstraction in the period 2000 – 2003. Research projects at the University of Salzburg, Austria, applied the LET from 2003 on and led to refinements so that the LET abstraction could be used in practice without significant computational and memory overheads. LET and its implications were thoroughly discussed at an embedded systems summer school in Salzburg with participants from academia and industry and with lectures from the ACM Turing award winners Niklaus Wirth and Joseph Sifakis:


From 2009 on TDL-LET was successfully used to model the timing behavior of Toyota's engine control system (ECS). The Validator tool was developed to compare the behavior of the conventional ECS and the TDL-based ECS. 
A special TDL subset was developed for safety-critical communication systems.

TDL for Daimler's

EQC series production

2016 – 2019

The TDL-LET is a basic software component of Daimler's next-generation electric vehicles that are shipped 2019/20. The Validator is deployed for Continental's functional developers world-wide in 2019.