A process and system for efficiently producing reference data that can be fed into a predictive model for predicting quality attribute concentrations in cell culture processes. A perfusion bioreactor is operated at pseudo-steady-state conditions and one or more attribute influencing parameters are manipulated and changed over time. As the one or more attribute influencing parameters are manipulated, one or more quality attributes are monitored and measured. In one embodiment, multiple quality attributes are monitored and measured in parallel. The quality attribute information is recorded in conjunction with the changes in the attribute influencing parameters. This information is then fed to the predictive model for propagating cell cultures in commercial processes and maintaining the cell cultures within desired preset limits.