ISO 18738:2002 specifies requirements and methodology for the measurement and reporting of lift ride quality during lift motion. It does not specify acceptable or unacceptable ride quality.
Lift performance parameters are often referenced in conjunction with lift ride quality. Parameters relevant to lift performance include jerk and acceleration. ISO 18738:2003 defines and uses performance parameters where they are integral to the evaluation of ride quality.
BS ISO 18738:2003 history
2003BS ISO 18738:2003 Lifts (elevators) - Measurement of lift ride quality