Finite element is definitely the most accurate way to check local stress for trunnions, but it is also more time consuming.   We are using WRC 537/107, which allows us to do a much faster analysis; however, the problem becomes in the ratios that limit the use of WRC 537/107.  It seems all too often we run into situations that fall outside of the curve parameters, and then we are “Off the curves”.  In those cases, we are reverting to a more simplistic analysis using the Line load method from the Pressure Vessel handbook by Bednar.