This means that rather than having targets for the number of women, say, in senior positions, it aims to make the business benefit from the contributions of all employees, whatever their race, gender, background or personality.
In the US - where the term originated - some companies are using the idea as the basis for actively seeking to recruit different types of people - in the hope of better understanding their market or even discovering niches that they might not otherwise have considered.
Prompted in large part by imminent changes in demographics that are supposed to reduce drastically the traditional white male workforce in coming years, consultants are warning industry that it must learn to manage this diversity or die. In Europe, where the population shifts are not likely to be so dramatic, the emphasis has been more on the business benefits of the concept.
According to the authors of a new book, the basic concept is that the workforce consists of a diverse population - due to such visible differences as race and gender as well as invisible ones, such as personality, background and workstyle.
But it is not enough for the company to point to these various types of people on the payroll. The premiss behind managing diversity is that 'harnessing these differences will create a productive environment in which everybody feels valued, where their talents are being fully utilised and in which organisational goals are met,' say Rajvinder Kandola and Johanna Fullerton in Managing the Mosaic: Diversity in action, published by the Institute of Personnel and Development, which is holding its annual conference in Harrogate this week.
The aim is to encourage companies - and hence their managers - to celebrate the differences in their staff rather than seek to assimilate them. At the same time, though, the authors - occupational psychologists at the Pearn Kandola practice in Oxford - are keen for business to escape such stereotypes as women being better at interpersonal skills. It may sound positive, but can be turned round to be used as the basis for excluding them from high-status areas.
In another book, Gaining Competitive Advantage from Diversity, by Peter Herriot and Carole Pemberton, which is due out next month, the different approaches are highlighted by comparison to different meals.
Assimilation is known as the Vindaloo model, whereby everything that is put in the dish ends up tasting the same. There is also the Nouvelle Cuisine approach, in which a delicate decoration is put on the side of the plate, since we are not quite sure whether to eat it or not. Finally, there is the traditional Sunday lunch, in which roast beef, Yorkshire pudding and roast potatoes are all valued and regarded as indispensable.
IDV - in common with other parts of the Grand Met group, which incidentally took up diversity when it took over Pillsbury in the US - has shown a commitment to this last approach.
Mission statements are notoriously vague, but IDV has included in its statement valuing the diversity in its global workforce and building such differences into 'a corporate strength'.
Nor is diversity seen as a 'stand-alone' issue. It is something that should run through other policies and processes, so that the company acknowledges that 'good ideas can come from anyone, anywhere in IDV', while documents concerning the building of new brands also contain such references to diversity as: 'Successful partnerships are built on mutual respect and the ability to listen to, understand and benefit from other people's points of view and experience.'
Mr Kandola and Ms Fullerton include in their book practical advice on how companies keen to emulate Grand Met and other leading organisations, such as Levi and Xerox, can set up a model for managing diversity. They add: 'Having diversity presented in different documents in different ways and by stressing the business benefit ensures there is a greater probability that people will not only receive the message but also absorb and accept it.'
But managing diversity is not an end in itself. The authors agree that the issue is entwined with the ideal of the 'learning organisation'. It not only ensures there is a diverse pool of potential available within the organisation but also releases this potential and begins the learning process.