There was a time, not more than a few decades ago, when if you were General Motors you would attempt to own every part of your business. The assembly lines, the parts manufacturing plants, the stamping units, the ancillary units and even such parts of the business as the software that runs the business, the dealerships that sell the cars, the steel mills or even the mines that produce iron ore for the steel mills. And for good reason – you could not either trust others to savvy enough to produce and send you the material that you wanted when you wanted it, or the margins in each of those businesses were big enough for you to try and own all those operations.