Abstract : Machine grading of lumber has shown great promise in research studies for improving the efficient use of wood. But industry has been slow to put such research findings to use without clear evidence that the change from visual to machine grading will be a profitable one. Mill managers, for instance, need guidelines to consider machine grading and how it might fit into their operations. This report seeks to document those guidelines so that lumber mills may determine for themselves the feasibility of machine stress rating their product. The first portion of the report deals with the principles of stress grading by machine. In the second part, the methods of lumber yield assessment are described by an industry specialist who has been active in this area. The third portion, on mill mechanical analysis and cost analysis, surveys mills that presently use some form of machine grading--indicating flow diagrams and permitting installation cost estimates. (Author)