The world of high fashion used to be simple: houses would hold runway shows twice a year in Paris, Milan, London or New York, and the clothes would arrive in stores four or five months later. But in 2016 a seismic shift took place – and the implications for Australians are significant.

Driven by ever-growing demand from Asia, the advance of "fast fashion" retailers such as Zara and the inexorable rise of social media, some of the industry's most esteemed houses have disavowed the traditional spring/summer and autumn/winter groupings and decided to try something new.

In February, British behemoth Burberry announced its intention to make its biannual collections "seasonless" and mix cold- and warm-weather garments in a single offering. More significantly, it said its clothes would be available in stores and online immediately after each show.

Hours later, titan Tom Ford announced that he, too, would be adopting the so-called see-now-buy-now model from September. Other brands, including Vetements and Rebecca Minkoff, have followed suit.

"In a world that has become increasingly immediate, the current way of showing a collection four months before it is available to consumers is an antiquated idea and one that no longer makes sense," Ford said. "We have been living with a fashion calendar and system that is from another era."

The fashion industry has been grappling with this issue for some time. To satisfy growing consumer demand for variety and immediacy, and to service markets in the southern hemisphere, a growing number of houses have begun augmenting their biannual collections with smaller offerings. These capsule collections – including "pre-collections", "cruise collections" and "resort collections" – arrive in stores during the quiet months between summer and winter.

But with more collections being released than ever, and the growth of farflung fashion weeks such as Sydney's, the fashion calendar has become incredibly crowded. Juggling all these seasonal balls is proving difficult for designers, manufacturers and retailers alike.

"It's ridiculous," says Rosemary Wallin, a designer who also teaches at Central Saint Martins art and design college in London. "We have so many collections now. It's unsustainable and we need to change our thinking."

Simultaneously, the purpose of the biannual fashion weeks has been evolving. In the past, they were held primarily so retailers could preview collections and order ahead. But a host of factors – including the growth of the luxury industry, the internet explosion and the increasingly blurred line between fashion and pop culture – has turned these into events something else entirely.

"Today, the primary reason for producing fashion shows is to generate image," says Bjorn Bengtsson, an adjunct professor at the Parsons School for Design in New York and a consultant for brands including Pringle of Scotland and Ted Baker. "This stands in stark contrast to the original intent: to drive sales. No longer do buyers represent a majority of the audience. Their seats have been taken by bloggers and celebrities."

With runway shows now functioning primarily as buzz-building events aimed at consumers, the "see-now-buy-now" model makes perfect sense. "It definitely creates a sense of urgency," says Robert Ferris, head buyer at Australian luxury department store Harrolds. "And it is working for us: we are able to leverage the hype surrounding a runway show and continue the story in store. Tom Ford is the perfect example."

Ferris says the gradual introduction of the see-now-buy-now model may help safeguard the future of bricks-and-mortar luxury retail, which has been struggling to coexist with luxury e-commerce. Currently, online shoppers can order some high-fashion collections during the four-month window between runway and release, making them less likely to visit a physical store. But see-now-buy-now may make a trip to the mall more attractive.

"We have the advantage of providing immediacy," Ferris says. "The client will be able to go into a store [after the runway show] and obtain his desired product straight away."

There are other obvious benefits for Australian shoppers. Currently, Australian stores are among the last in the world to receive shipments of new collections. If houses start distributing clothing to stores before runway shows, shopping locally could become much more exciting. And, with less of a focus on the northern hemisphere's seasons, it should be easier to find weather-appropriate wear.

'It is always a challenge'

For local designers with global ambitions, the shift could prove similarly beneficial. Dion Lee, the lauded Australian womenswear designer, has long grappled with practicalities of maintaining a presence at home, where his clothes are created, and in the United States, where he dresses Hollywood stars and presents his collections at New York Fashion Week.

"We show in New York and follow the northern hemisphere seasons but our stand-alone retail presence is in Australia, so it is always a challenge to make sure we have the right product mix globally," he says.

Lee is something of a trend-setter: he has been mixing warm- and cool-weather garments on the runway for several years and says the move away from rigidly defined collections has proven both commercially and creatively liberating for his brand.

"We're introducing outerwear into our summer collections and lightening the colour palettes in our winter collections," he explains. "Our collections are becoming increasingly trans-seasonal."

Lee says designers as a whole have much to gain in the current climate, adding: "There is more freedom in this state of flux."

Even if some traditional high-fashion houses dislike the idea of dismantling the old calendar system, they may soon be compelled to do so. The tremendous growth of so-called "fast fashion" retailers such as Zara and H&M; – which mimic runway designs and sell them earlier at a fraction of the price – has generated an expectation among consumers that what they see on social media will be available to buy immediately, and much of it cheaply.

The financial case is compelling. Zara's net profit for the nine months to October rose 9 per cent on the previous comparable period  to €2.21 billion ($3.13 billion), its parent company, Inditex, said this month. In contrast, shortly before its "see-now-buy-now" announcement in February, Burberry reported flat revenue.

"The fashion consumer has adopted a buying pattern of mixing low-cost fast fashion with high fashion and it has served to legitimise the fast-fashion business and narrowed the gap," says Bengtsson.

But while he admits that high-fashion brands must now more than ever foster a sense of immediacy with consumers, he cautions against houses trying to shorten their development and manufacturing timelines. "That will be their demise," he says. "They can implement certain [fast-fashion] characteristics, but never their speed to market."

Instead, he expects luxury houses increasingly to keep their upcoming collections under wraps until they are ready to be sold. He also predicts the fashion calendar will be preserved – although its alignment with the retail world may slip.

"There is a certain amount of ego involved in the upper end of the industry," he says. "The fashion show is the biannual stage for self-indulgence."

And, he adds, it still has an important role to fill as a medium for artistic expression. "It helps to stimulate creativity in the industry."