Individuals differ in development stage or biological age. This difference can be taken into account when modelling the quality behaviour of various fruits and vegetables. Even on a batch level, the same principle can be applied, provided the variation within a batch is not too large. By applying the biological shift factor, i.e. a shift in calendar time, the effects of different growing and harvesting condition can be included in modelling quality behaviour, which widely opens alleys for producing models applicable in the entire globalised food chain. The variation in biological shift factor over individuals in a batch and over several batches seems to exhibit a normal distribution pattern.