"product to utility substitution gives you ample warning in advance, often ten years or more." #readingToday  

I need to emphasise that product to utility substitution gives you ample warning in advance, often ten years or more. However, this assumes you have reasonable levels of situational awareness and it's situational awareness that is the key to defence. If you exist in a firm which has little to none (the majority) then even that which you should anticipate comes as a complete shock. Even if you have the situational awareness necessary to see the oncoming storm then you'll still need to manage the inertia you have to change but since you've got lots of warning then you can prepare.