Three small letters have had a big effect on Robert Wiseman's business strategy since the latter part of 2005 - N, P and D.

The business is currently ranked fourth on our Top 50 list and has experienced positive growth in sales during the past 12 months. It remains very much a family company, but has invested heavily in NPD, including the launch of ­Puriti fresh whole and semi-skimmed milk that has more than double the shelf life of standard.

Puriti has been designed for holidaying Brits, and the company started distributing it to Spain in July. The launch of ­Disney products under The Incredibles brand at the start of the year also received a positive reception, and the success of The One milk with 1% fat at the end of last year has enabled the business to trial a new 750ml size. Joanne Rae, marketing manager, says: "We are always looking to develop our products and keep them to the fore." n