1998-2003 Dodge Durango simultaneous design and engineering
Durango's concept to production timetable was the shortest in corporate history - 132 weeks. This was achieved through seamless, simultaneous design and engineering. There were no Design Office to Advance Engineering to Product Engineering hand-offs. Advance, Body, Interior and Chassis Engineering design personnel were co-located to form a mini-platform team.
All aesthetic design work was done electronically. A proprietary, leading-edge-design software package called the Chrysler Data Visualizer (CDV) became available during the latter stages of Dakota design and was used extensively for Durango. Working from design sketches, designers used CATIA to design the panels and CDV to create representations with all the visual qualities of a physical object. Outer panels, inner panels and interior trim were superimposed to assemble a complete vehicle. Surface approval was granted on the basis of CDV images projected on a screen. Design engineers, stamping engineers and suppliers worked simultaneously with the aesthetic designers to resolve feasibility issues and complete the design. On-screen visualization actually enhanced issue resolution because fit, finish and interference issues could be visualized full-size and viewed from any angle. Unlike any program in corporate history, clay models of the exterior and fiberglass derivatives from it were made only after the design was approved. As design work progressed further, these models became outdated but surface integrity was maintained by CDV. Because changes were easy to visualize, designers experimented with surface aesthetics rather than having to stick to an existing clay model. Using CDV, the exterior surface was designed in three weeks, and the interior was completed in half the normal time.
Ongoing consensus was maintained as each change to meet vehicle objectives was immediately scrutinized by all affected areas. Major focuses of the process were the packaging of three rows of seats within the proposed exterior envelope and frame commonization to minimize investment. CDV was invaluable for assuring interior package integrity. Because CDV allows viewing of the vehicle from any point in space outside or inside the vehicle and also allows any panel (such as a window) to be made transparent, it was used for outward visibility studies. Pillar size and placement issues, size and placement of the CHMSL lamp, etc., were quickly resolved using CDV. Structural panels were also easy to move and redesign to maximize interior room using CDV. Issues concerning panel attachments and space utilization were resolved in the design process because surfaces were easy to move electronically, resulting in more representative program vehicles, resulting in fewer issues to resolve later and better overall quality.
Structural design was speeded along by a substantial staff of structural analysts. Even before benchmark studies to establish structural objectives completed, a simplified, hybrid FEM (finite element model) was created from the pickup truck model by adding beam elements. Within three months of program inception, four prototype vehicles, using tubular structures based on the hybrid FEM for bodies, were undergoing initial ride and handling evaluations.
Recognizing that time was of the essence, a two-track process of exterior and interior surface development for prototype vehicles was followed. State-of-the-art quick-tooling technology and preliminary surface data were used to build early design-intent program vehicles suitable for engineering test and development purposes. Later program vehicles were built from updated tooling with a close representation of the final surface to demonstrate feasibility. Only production tooling was built with the final surface. Because the parameters of this vehicle were unique, Advance Engineering built a full-size dimensional interior model and seating buck as soon as design data was available. Milled from structural foam using CATIA computer design data exclusively, the model included all interior surfaces and window openings (for visibility checks).Accurate doors and a lift gate were formed from carbon fiber sheets based on the CATIA data. Functional seats were built by the supplier and the assembled unit was used to verify seating accommodations, entry and exit room and head clearances. A jury of employees was used to make subjective evaluations of comfort and accommodation provided by the unique seating package.