For businesses, the benefits are manifold. Over the past 20 years, absenteeism rates have soared by 20 per cent, and in 60 per cent of these cases the reason is thought to be a lack of work-life balance. In addition, says Carol Savage, director of the Resource Connection, "customers are more demanding and do not want to be served only between nine and five. And many organisations need staff working at times when they can communicate across different time zones." Advances in technology are relevant, too. "Being in a fixed location is much less important than it used to be, so employers can be creative with the use of desk space and make great savings in the process."
For the secretaries themselves, there are also obvious advantages. "It provides the opportunity to spend more time with the kids, to study, to stop spending so much time commuting, to prevent boredom or simply to work less," explains Paul Jacobs, communications officer at Office Angels. "It also enables people to take advantage of their body clock. Some people, for instance, work much better in the evening than the morning." Indeed, the Institute of Management recently found that 55 per cent of secretaries are key users of flexible working.
At St Luke's, an ad agency based in London, not only are there flexible working hours and locations but nobody is tied to their own desk - a trend that is catching on in an increasing number of organisations. "You just work where you want when you come into the office," explains marketing and new business manager, Juliet Soskice. "We feel it's important not to judge someone's success by the size of their sofa, and to get everyone to mix with everyone else who works here. That way, you have fun and you are therefore at your most creative."
But inevitably, flexibility has its potential pitfalls. This has yet to be researched, says Personnel Today, but employees may regard their office and desk as a sanctuary and security - a haven from a woeful home life. Joyce Fellman, a 36-year-old PA who works for a life-insurance company, is a case in point. "Like many of the secretarial staff here, I was offered the opportunity to work more from home and do flexi-hours, but I actually like coming into the office every day, particularly as I live on my own and I don't have much self-discipline when it comes to working outside the office. I also enjoy my evenings and always like to keep them free." In fact, there is understandable concern that flexible working unfairly discriminates against the single, who are forced to endure heroically long hours, while their colleagues with children hot-foot it from the building.
Other studies reveal that flexible working can encourage all employees to work too hard. "If people work from home, say, and take an hour off to pick up the kids from school rather than taking a quick coffee break, it has been found that they tend to feel guilty and work more hours than necessary to make up for it," emphasises Cary Cooper, Professor of Organisational Psychology at the University of Manchester Institute of Science and Technology (UMIST), who adds that there are unique problems for secretaries. "The introduction of `flexible working' can wind up meaning `at my beck and call all the time' - particularly if you are a PA and your boss wants you to be available when he or she is available."
The introduction of mobile phones has added to this problem. Sally Henbury, a 28-year-old PA in the City, explains: "Like many flexible PAs, a mobile goes with the job. Not only because I work from home, but because I never know when he'll need me. Sometimes it's 5pm, sometimes it's 5am."
As for "hot-desking", business psychologist, Bridget Hogg, says: "If it's not an employee's choice to get rid of their desk, they may feel they have no space to call their own, and suffer quite a severe loss. Without any personal territory, many people can feel unstable and undervalued - especially in today's insecure working climate."
Flexible working frequently features highly in the causes of industrial disputes. As a Cleveland fire-fighter told a rally against a new flexibility drive in May, "Not one of us will benefit. There will be fewer of us going to more fires." It's a comment that could be adapted to describe many jobs.
The solution? Negotiation, says Cary Cooper. "If you are entering a job with flexible working practices or you are already in a job where it has been proposed, ask to sit down with your boss and discuss exactly what it will mean in practical terms. Make firm ground rules which you can both have in writing, and ensure that you will both gain from it. For example, if you want to work from home one morning a week, accept that Monday might not be a good day for your boss since it's the beginning of the working week. Likewise, if your boss wants you to work evenings, explain which ones will suit you. If you have problems about hot-desking, say so. It will make you more productive in the long-run."
"No one is trying to argue that flexible working is a solution for every job," says John Knell, head of research at the Industrial Society. But the chances are that with adequate preparation and mutual agreement, you and your employer could gain a great deal from it.