Design defect cases focus on flaws and errors in a product's design that make it unreasonably dangerous to consumers. If a product has a design defect, all products of the same type have the same defect. This is in contrast to a manufacturing defect, which is created once or up to a few times during the production of a batch. Unlike other types of products liability cases, which can be brought against a seller or assembler, a design defect case is usually only brought against the manufacturer responsible for the design of the product at issue.
What Does a Plaintiff Have to Prove in a Design Defect Case?
A manufacturer's liability for design defects arises when a plaintiff is able to show the product posed a foreseeable risk of danger to a consumer using it for its intended purpose. For example, if a plaintiff is able to show that an SUV tends to roll over when its driver needs to swerve to avoid an object or other hazard, this might be a design defect. Similarly, if a plaintiff's hand is amputated while using a power tool that has a plastic guard with openings that are too large, the plaintiff may be able to bring a products liability suit against the manufacturer of the tool, arguing that it was foreseeable that a person's hand would slip through the guard and be injured.
The Alternative Design Test
In some jurisdictions, a plaintiff must show that it was practically and economically feasible for the manufacturer to adopt a safer design (sometimes called the “risk-utility” test).
In some jurisdictions, it is not enough to simply show a design defect. The plaintiff must also show that it was possible for the manufacturer to adopt a reasonable alternative design. The rules vary depending upon the state, but a plaintiff in those jurisdictions will likely have to prove that the alternative design was feasible from both a practical and economic standpoint, and that it was not in opposition to the product's function.
That means, for instance, that in the power tool example, the plaintiff would need to retain an expert who could show how the tool and the guard should have been designed to avoid injury. The expert will also need to show that the alternative design was not prohibitively expensive. The cost of adopting the alternative design must be less than the cost of the medical bills of claimants injured by the power tool to be economically feasible.
The court may ask for an estimated cost of creating the power tool. It may also estimate the average cost of the medical bills associated with power tool injuries. This sum will be multiplied by the estimated number of power tool injuries. If the cost of making the power tools with the alternative guard design is less than the cost of the medical bills from power tool injuries based on the existing guard, the alternative design would be considered economically feasible.
The Consumer Expectations Test
In other jurisdictions, a plaintiff must show that the product posed a risk greater than what the ordinary consumer would expect.
Some jurisdictions follow the consumer expectations test, rather than the alternative design test. The consumer expectation test asks whether a product poses a risk of danger that exceeds what the ordinary consumer would expect. The arguments in those jurisdictions often hinge on who the "ordinary consumer" is.
When a product has a design defect, the plaintiff most often sues on the basis of negligence or strict liability. The negligence cause of action will allege that the manufacturer knew or should have known of the risk associated with the design. A plaintiff has a stronger argument if he or she can show that an alternative design would not have reduced profits significantly. A strict liability cause of action alleges that the manufacturer placed a defective product posing an unreasonable risk of danger into the stream of commerce.