While there are different ways to assign priorities to a given number of processes,

the rate-monotonic scheduling assignment, in which processes with a shorter period have a higher priority, has been shown optimal if the processor utilization is less than 69% [LL1973](#LL1973).

However, data consistency is often an issue when preemptive scheduling is used and if data is being shared across multiple processes via global variables. Due to scheduling effects and varying execution times of processes, writing and reading these variables could occur sometimes sooner or later. This results in an latency jitter of update times (the timepoint at which a variable change becomes visible to other processes). Race conditions can occur when multiple processes access a variable at the same time. So solve this problem, the concept of logical-execution time (LET) was introduced in [HHK2001](#HHK2001), in which communication of data occurs only at pre-defined periodic time instances: Reading data only at the beginning of the period and writing data only at the end of the period. The cost of an additional latency delay is traded for data consistency and reduced jitter. This concept has also recently been applied to automotive applications [NSP2018](#NSP2018).