The drive to increase engineering productivity and decrease expensive hardware testing has resulted in the widespread application of the finite element method of structural analysis to diesel engine components. The scope of finite element analysis at Detroit Diesel Allison has been expanded far beyond the simple investigation of mechanically induced component stresses. The DDA developed, multipurpose finite element code, STRATA, has been used to analyze critical deflections, combustion induced thermal stresses, the probability of survival of ceramic structures and assembly parameters for ceramic-metal composite components. Finite element analysis has also been combined with the concept of factorial experiments to optimize new component designs. Specific examples of each application are discussed including piston kit, cylinder head, and valve gear components. Analytical results are interpreted and unique characteristics highlighted.