Integrating safety features may lead to changes in vehicle interior component designs. Considering this complexity, design guidelines have to take care of aspects which may help in package feasibility studies that consider systems performance requirements. Occupant restraints systems for protection in side crashes generally comprise of Side Airbag (SAB) and Curtain Airbag (IC). These components have to be integrated considering design and styling aspects of interior trims, seat contours and body structure for performance efficient package definition. In side crashes, occupant injury risk increases due to hard contact with intruding structure. This risk could be minimized by cushioning the occupant contact through provision of SAB and Inflatable IC. This paper explains the methodology for deciding the package definitions using Knowlwdge Based Engineering (KBE) tools.The logic in the applications helps to generate package layout requirements for airbag module configurations as well as interior components. The protection zones for occupant body regions such as thorax for SAB and head for IC could be defined using the applications. The location of chambers to be inflated for protection could be arrived at thereby providing extent of airbag envelope required. The variations arising out of occupant anthropometry, seating attitude have also been considered. Package clearance requirements with interfaces like side door and pillar trims, seat belts, could be identified. Package constraints for hard components which increase occupant injury risk can also be defined. The requirements to ensure stable deployments, particularly for IC, could also be analyzed. The application outputs are available as summary reports, data which could be further used by design teams. The applications have been successfully validated on vehicle programs.