Target has been busy upgrading its supply chain, and this holiday season marks its biggest test yet.

Early last year, the retailer said it would pour $7 billion into investments to turn around its business over the next three years. A portion went into bulking up its delivery options — making it more convenient for people to shop in Target stores and online. While Target declined to say exactly how much it spent on those efforts, it's easy to see the results. It has rolled out free two-day shipping, acquired a transportation company and is adding services like curbside pickup and same-day delivery in major metro areas.