Design validation is important in project management because even if the product meets the verification aspects, if it does not meet the user needs the product will not be used or sold and the time and money spent on development would have been a waste. Validation is part of why pre-clinical testing is done. For example, a hip implant could be designed and meet the design inputs but until it is surgically implanted and analyzed you won’t know if the device meets customer requirements. You try and create specifications and constraint that make sure the customer needs are met, but some are difficult to quantify and need validation to be sure the inputs equal the customer needs.