Presented by Graham Stewart. Douglas Fraser visits AG Barr's headquarters in Cumbernauld to meet Robin Barr, who's standing down as chairman this week after half a century with the business behind Scotland's other national drink, Irn Bru. But how easy is it to create and establish a truly successful brand? We find out with the help of Ken Dixon from the Edinburgh-based advertising agency Newhaven Communications, and entrepreneur Jonathan Engels, who's started taking on one of the most competitive industries in the world by launching his own brand of distilled vodka. Once you've established your brand, the next challenge is keeping it. Sally McNair reports on Scottish companies which fail to keep an eye on their hidden assets. And Colin Borland from the Federation of Small Businesses tells us why his members are calling on the Scottish Government to investigate payment times to subcontractors involved in public works.