You need to establish that the benefits of using the product as designed do not outweigh the risks of harm associated with using it. Among the factors considered are the cost of the product, the scope of the defect, and the severity of the injury. Usually, it is necessary to retain an expert to testify about design defects in order to meet the risk-utility test. 

Risk/Utility: The “risk/utility” standard is” a test balancing risks and utilities or, stated in economic terms, a cost-benefit analysis.” Tincher, slip op. at 98. “The risk-utility test offers courts an opportunity to analyze post hoc whether a manufacturer’s conduct in manufacturing or designing a product was reasonable, which obviously reflects the negligence roots of strict liability.” Id. at 99.