He was recruited as a very senior director in a very large City law firm. His work went well but the thing that really bugged him was the pass he had to show every time he went into the staff restaurant. The words 'non-lawyer' were printed on the face of it (for non-lawyer, read 'second-class citizen').

Demonstrating examples of discrimination and distrust from the profound to (in this case) the silly, law firms have been regarded as dangerous (and, perhaps worse, daft) territory for professional managers. Heaven knows how many of these talented people decide not to enter the sector but we do know that, among those who enter the den, their tenure will be short. Marketers last an average of 2.4 years in the same firm, according to research from recruitment consultancy First Counsel. Finance people make it to 3.3 years. Interestingly, almost all then stay in the professions, suggesting that the job is great but moving is the only way to obtain roles that match enhanced skills and experience.

Steve Manton, consultant to law firms at M Consulting, describes the typical trajectory of the two-year marketer: "The marketing partner recruits a marketer, usually a young female of some experience but not used to handling partnerships. They give her no support and stick her in a cupboard to work on her own. After two years nothing has happened, and the partners say: 'We tried marketing but it didn't work…'"

OK, Manton is describing a scenario more common 10 years ago than today, but its legacy remains. While some firms are making huge leaps of perception and management (not to mention profits), many more are putting their whole future in peril by managing themselves like a group of eccentrics sharing a kitty in a pub. This is an issue that we at the Managing Partners' Forum (MPF) have been addressing since September 2004, when we launched our high-profile 'unsung heroes' campaign to highlight the importance and contribution of professional managers in professional firms.

Extraordinary changes are happening in the legal market – whether in technology, globalisation, the advent of 'Tesco law' or the financing of firms – and the survivors will be those that find a sure way to keep their existing clients and find profitable new ones. In some cases, they may do this by traditional, albeit slightly shabby, means, such as being the only firm in the village or having clients who are too old and tired to want to change advisers. But in most cases – especially for large commercial firms with any pretensions to sophistication – there is nothing for it but to apply a bit of intelligence, use modern management methods and recruit specialists in fields such as finance, human resources (HR) and IT. Oh, and then, of course, the firm needs to treat those specialists well enough to hang on to them.

The best advice for most firms is to study their own commercial clients. How do successful organisations recruit the best talent? They get a good reputation in their field; they show that they are reliable, long-term employers; they make themselves transparent enough that potential recruits can understand why they are successful and trust the messages that are being shared; they offer career development; and, increasingly, they try to keep their workforce stimulated and proud of the fact that they work for that organisation. Or – to translate these activities into specific business goals – they work on managing their brand, producing sound financial results over the long term, having good internal communications, and maximising the resilience and energy of their employees.

Let us take brand management as an example. A business with a tremendous brand – Marks & Spencer, for instance – has an immediate head start over other employers trying to recruit from the same pool. Even the least knowledgeable candidates will know immediately that such a company has a track record, is unlikely to go out of business tomorrow and will look good on their CV. They might even accept a lower salary to work for such a firm compared with one that they perceive to be risky. And when a firm goes through difficult times, as most do, a well-established brand can protect its reputation against some of the knocks that would destroy those that have neglected their brands.

One of the bizarre facts about the legal profession is that, despite being far older than most of the businesses it advises, it has not yet developed a recognised method for valuing its own business. Firms cannot be reliably examined by outsiders or compared by anyone. Potential recruits are taking a much bigger gamble in going to a law firm (because it is a relatively unknown quantity) than to a listed company (whose value and brand are under constant discussion and observation through the production of financial statements and the views of investors, as shown in share price movements).

By the middle of next year, however, the top 30 or so UK law firms will for the first time be given an external brand valuation that takes into account the same factors as other businesses – earnings projections, profitability, quality of clients and products, employee satisfaction, and the loyalty and strength of the management team. This pioneering project, which involves valuing each of the world's 500 leading professional firms, is being undertaken by the MPF in partnership with specialist valuation consultants Brand Finance. (See Legal Week, 18 October, 2007, page one, and the Legal Week Big Question survey, 1 November, 2007, page eight). We know that some firms would rather that we did not do this. But then there has always been a very powerful element in the legal profession which opposes change.

We sense that the reactionary voices are fewer in number now than a decade ago as the realisation has dawned that the pressures are overwhelming. When external investors arrive sometime after 2010, firms will be subject to an unprecedented level of scrutiny. Many will be forced to overhaul themselves or to become much poorer. Thousands of principals and partners expecting a fairly comfortable retirement will find that the equity value of their own firm has been downgraded. The pity is that highly talented people in their own area of expertise are failing to realise the value that can be added by experts in finance, HR and other management disciplines.

We predict that within 10 years there will be the biggest meltdown ever in the UK legal profession. In the brave new world, it will make as much sense for a fee earning partner to be running the marketing team as a marketing professional to be running an M&A matter for a client. External investors are not going to react well if they find that partners rather than professional managers are calling the shots. The people who will make the biggest difference in this raw competitive market will not be the lawyers but specialist managers.

The results are becoming plain to see in firms that are investing in their marketing, knowledge, risk and other departments. Allen & Overy, for instance, (which, significantly, talks of 'other professionals' and not of 'non-lawyers') has become famous for the continuous development and training opportunities it offers. Baker & McKenzie – arguably the most genuinely international firm in the world – has demonstrated how seriously it takes marketing by having Beverly Landais, its UK marketing head, participate in decisions on strategy, targets and other management issues. Nottingham-based Browne Jacobson, winner of the MPF European Practice Management Award for best managed firm in 2006 and for best marketing campaign in 2007, may be less well known, but its successes are just as clear to those who look at the evidence. Helped by a team of senior specialist managers, it has grown its turnover four times over, by organic means alone, in the past decade.

Browne Jacobson had the guts to pick a former marketing manager from Boots, Sarah Warnsby, to be its marketing director. If she is right – and we think that she may well be – then law firms are going to be shaken upside down by the forces of competition. Just looking at one issue alone, her views could make the profession's collective blood run cold. She believes that the arrival of retailers – such as Tesco or Boots – will destroy traditional fee charging practices for commercial as well as consumer clients. "Hourly billing is on a time-bomb to disappear. Law firms have to get their head around a completely different method of charging," she says.

Whether Warnsby turns out to be right, half-right or wrong, she knows more about pricing than most lawyers, however intelligent they may be, because she has spent her working life studying the issue. Our profession needs to be employing more people like her and publicly valuing their contribution in helping steer the right course as competition gets more intense.

Nigel Knowles is MPF chairman and joint chief executive officer of DLA Piper; Richard Chaplin is MPF founder and executive director.