@Leon Hulett "I don't see any value to it." Did Leon mean to d or to t? I should make it clearer but can't do subscripts. Some, like d for instance, are more like Dvp meaning disruptiveness as a value perceived. I is perceived too. R and T are regular old values. i.e. if it costs more, and/or it takes longer to integrate, you best have a darn higher I!