Six Sigma Methodology Application for Performance Evaluation of Different Configurations of Seat Belts Reinforcements during a Project Development

The relation cost versus performance in the design of an automobile is crucial for its success. These two characteristics, much like the project development timing, are closely related to the attributes that the new design must achieve (e.g. weight, fuel economy, torsional stiffness, NVH, safety, etc.). In this respect, the design optimization of body reinforcements (i.e. part thickness, quantity of reinforcements, and number of spot welds) contributes greatly to a sound and robust project concept. This paper describes one application of 6-Sigma methodology to evaluate the performance of different configurations of seat belt reinforcements resulting in an optimized concept that achieved the proposed performance targets with weight and sub-assembly complexity reduction. Using a Design of Experiments (DOE) and Finite Element Analysis (FEA), each proposal was evaluated for its resistance to plastic deformation. Through a linear regression analysis of the results obtained, it was possible to estimate the influence of each variable on the performance of the assembly and achieve an optimized design. This article demonstrates the proposals evaluated, the system's required targets, the regression analyses, and the related business case.