Scout around for the top reasons why businesses fail, or the most difficult issues that business owners have to deal with in South Africa, and you'll find no shortage of suggestions.

Lack of access to finance is a favourite (and happens to be wrong, by the way. If anything, a lack of access to finance has saved many beginner business owners from making their mistakes even more costly), as well as lack of business skills (definitely right); inflexible labour laws (wrong, it's the lack of knowledge on how to work the labour system that causes headaches for business owners); the badly trained South African workforce (right up there with lack of business skills); red tape (yes, but it's overrated); and a bad attitude towards record-keeping and financial management (definitely).

Business trainers, consultants and experts all trot out some variation of these factors, and almost all of them fail to include a major source of business pain - partnership problems.

How strange that such a potentially lethal force is ignored by most how-to books and training courses. Is it because the personality problems between business partners are considered to fall outside of the realm of business? Not if you take into account the direct influence partnership politics has on the bottom line of a business. Also, entrepreneurship studies certainly don't shy away from other "personal" issues - the personality of The Entrepreneur has been analysed to death.

Perhaps it has more to do with an assumption that the default owner-managed business has only one owner; that a situation where there are multiple shareholders is the exception. This may be true for smaller businesses, but certainly not among those with growth ambitions. Operating in the bigger leagues usually requires the pooling of resources, and many entrepreneurs eagerly join forces to stand a better chance of surviving the dangers of business growth.

Few consider the possibility that the biggest danger may lie in the very partnerships they forge. So much can go wrong in a business partnership that something usually does - not always fatally so, but certainly often enough to warrant much more research on partnership problems and how to avoid them.

How do they go wrong? Let me count the ways.

After a few years in business, ambitions can start to diverge - one partner wants to grow, the other wants to avoid risk.

Different partners invest emotionally in different ways in a business - one loves the workshop, the premises, the staff; the other wouldn't mind selling it all when the price is right.

A personality trait that seems quirky around a braai can become intolerable around the boardroom table.

One partner starts suspecting, or knows, that the other partner is not pulling his weight.

Partners prevent each other from pursuing sidelines for fear of split loyalties. Or resent each other for having sidelines.

A partner who is excellent on the workshop floor turns out to be dreadful in the boardroom, but resents being left out of top management as the company grows.

A partner, by virtue of being a founder-owner, occupies a job in the business in which he isn't very good, but commands double the going salary. Woe to any other partner who tries to rectify that mistake.

Business owners tend to value their businesses by the amount of sweat and tears they've invested over the years. The result is that we almost all have a vastly exaggerated idea of the value of our businesses. Try telling that to a partner who wants to or has to exit a business by selling his shares to the other partners.

The operational partners start suspecting the partners who control the finances of skulduggery or vice versa.

An unequal partnership, even if set up in a scrupulously fair manner so that the partner who came in with the majority of resources has the bulk of the shares, tends to entrench the dominance of the one partner in perpetuity. This is a major dilemma for South Africa's BEE project, at least as far as owner-managed businesses go.

Differences in style - the treatment of staff, clients, paperwork, moral dilemmas, even office furniture - can become anything from irritants to major chasms. It's like marriage, but with money in the place of love.

And business partners who happened to be married to each other? When it works, it can be a really powerful force in business, but they say it's very difficult.

Pointing out the potential problems of business partnership is the easy part. It's what to do about them that is unstudied and uncertain. There is a lot of advice floating about, based on personal experience and anecdotes, but it tends to be of the one-sided, defensive kind, such as "never take a minority share in a business", which doesn't solve the dilemma for the minority owner.

A good body of knowledge and best practice is building up around succession planning in family business, which seems to hold a lot of value for business partnerships generally. It has to do with professionalising a business, separating ownership from management functions, and providing clear exit paths for shareholders. If you can find and afford such advice, do so.

But so far there is only one certain rule of business partnerships: don't go into them unless you really have to.