Thank you gentlemen , I will be more specific: As far as I know there is no AFM data from Boeing concerning stopping distances on contaminated rwys. There is advisory data issued in the QRH describing stopping distances on different braking actions (good , medium and poor) for a specific landing weight.
When using these data (+ 15% ) do a commander have to stop within 60 % of LDA?(JAR-OPS 1.520)