Family-based dispatching (FBD) rules have been proposed to reduce setup time and improve system performance by grouping similar types of jobs for joint processing. Although variations in due date, setup and processing times are frequently observed in real situations, they have received little attention in the development of new family-based dispatching rules. Furthermore, due date-related performance measures have not been considered during the past two decades as new family-based dispatching rules have been developed. Several new family-based dispatching rules are developed in this research to improve due date-related performance. The potential of the newly developed family-based dispatching rules is investigated through an extensive simulation study. The system variance including variations of due date, setup and processing times is also considered as a key factor in this research. This research compares representative existing family-based dispatching rules with the newly developed rules to show their performance. Moreover, performance differences arising from different locations of family-based dispatching are also examined. The results of this research demonstrate that the newly developed family-based dispatching rules improve system performance with regard to the system variance and location of family-based dispatching as well as several other important factors.