"Who steals my purse steals trash; 'tis something, nothing; 'twas mine, 'tis his, and has been slave to thousands; but he that filches from me my good name robs me of that which not enriches him and makes me poor indeed."

Those of you studying Othello this year will recognise this quotation about the importance of a person's reputation.

Nowhere is the loss of your good name more damaging than in business, particularly in the area of franchising.

Last October, the Health Service Executive made an unpleasant discovery in the Stephen's Green Shopping Centre in Dublin - some cockroaches had decided to take up residence in a sandwich bar on the first floor. An O'Briens Irish Sandwich Bar to be precise - one of two at the centre held by different franchisees.

The owner of the O'Briens franchise reportedly took swift legal action to prevent the operator of the outlet from continuing to use the chain's name and branding.

Clearly, the aim of this damage-limitation exercise was to minimise the negative effect on the valuable brand and other franchisees.

The franchising model - whereby a franchisee buys the rights to operate a business format created by a franchisor - can be an excellent means of achieving rapid expansion, but it is not without its risks.

O'Briens is the fastest growing franchise in Ireland and there are now more than 300 outlets in the chain.

But the pest infestation incident highlights the vulnerability of a brand once a business owner gives someone else the right to use it.

The process of recruiting suitable franchisees is therefore crucial.

"If the franchisor gets the franchisee recruitment programme wrong . . . and starts recruiting bad apples . . . those franchisees will reduce the reputations of the other franchisees and the brand," explains Michael Bradley, chief executive of the Irish Franchise Association.

Despite this potential pitfall, the argument in favour of the franchise system is very persuasive. The success rate of franchises over the first five years is a staggering 93 per cent, compared with just 50 per cent for start-up businesses, according to Bradley.

Why exactly are franchises so successful? "The franchisee operates under a proven business format," he says. Franchisees are buying into an existing business so they hit the ground running, because all of the teething problems will already have been ironed out.

Another critical advantage is that the brand will already have established a reputation.

"The products and services will already be well known, which should enable the business to grow more rapidly," he says.

Reputable franchisors will also provide training, either on the job or before the franchisee gets their outlet up and running, so experience in the field usually isn't necessary.

McDonalds even runs a hamburger university, which is attended by 5,000 students each year, including potential franchisees.

Under the franchise model, franchisees pay a regular fee to the franchisor, generally in the region of 7 per cent of annual turnover, in return for initial and ongoing training, and sales and marketing support.

"Usually a franchise will take a small percentage of the franchisee's turnover and put it into a central advertising or promotional fund," Bradley says.

This means that individual franchisees don't have the responsibility of looking after marketing and promoting the business as it is done centrally, and they can concentrate all their efforts instead on running their outlet.

Once a chain builds up a critical mass of franchisees, it will often use them for research and development purposes, he adds. For example, O'Briens brings all of its franchisees from around the world together once a year and uses their input to develop the brand.

Franchising is growing increasingly popular in Ireland, particularly in the services industry.

The Irish Franchise Association runs seminars roughly four times a year and, in the Dublin region alone, has encountered at least 20 businesses at each seminar considering franchising as a means of expansion. Roughly half of these go on to develop a franchise, Bradley says.

For those who want to build an empire from scratch, put their own name to something and be completely in control of their own destiny, franchising probably isn't the right option, as franchisees must run the business in strict accordance with the operations manual or risk losing their franchise. Starting their own venture might be more suitable.

However, for anyone who aspires to run a profitable business, but is put off by the high failure rate of start-ups, buying a franchise can be the perfect solution.

And fortunately there has never been more choice.