Technology Readiness Level (TLR)

The TRL gives a value in what state the currently used technology is. By PDR all subsystems should be at TRL6.

Determine the TRL

The TRL is not an exact science, what which TRL is should be defined in the Team, there also are judgment calls when it comes to define the correct level. Even a flight proven system at TRL9 can fall back to TRL5 or even lower if the environment changes.