AP & AM Colloquia. Many challenges in pediatric cardiovascular surgery are essentially engineering design problems, though they are not typically approached as such. About eight years ago, we formed a small engineering team at BCH to provide quantitative surgical planning as a clinical service. What started as a bounded effort to use computational fluid dynamics to plan the details of one specific type of surgery has grown to include quantitative heart valve repair, computational vascular patch design, and more. This talk will describe some of the successes and challenges in applying ordinary engineering approaches in an extraordinary environment.