Bar-codes, electronic point sale systems, hand-held terminals… information technology has transformed retailing.

At Marks & Spencer’s IT centre, mainframe computers monitor what’s been sold in all its stores and order up new stock. Computers control every step of the M&S national distribution system. And IT isn’t confined to inside the supermarket, but also links it to suppliers. We visit one of M&S’s suppliers where computers also control the whole manufacturing process.

M&S has an Internet-based shopping system so you can even buy from the comfort of your home. IT makes superstores more efficient and powerful - but what about the impact on environment and smaller shops?