Why do start-ups fail? Why do scaling firms flame out? Why do star firms lose their lustre and fade away?

Many reasons surface with “money running out” to the fore. Alas, cash is more often a symptom than the cause of the downfall. Understanding why is especially important as we open up again. Time is short, customers needs and behaviours are changing, and new technologies and innovations will become a flood in the coming months.

Research consistently shows that the biggest cause of the demise is product market fit. Or to be more precise as Brian Balfour, founder of Reforge, puts it, market product fit. Start with the customer, not the product.

This is not a criticism and my heart is with those who have failed. I have been there myself. You are the ones who tried. You are the ones who had the courage to step forward. I applaud you. One hundred years on from our days of peak invention, Scotland remains uncomfortable with failure. How we treat failure as a society is holding us back and from learning.

It is obvious but cannot be repeated enough: the answer is customers – a steady flow of customers who value the product and feel compelled to tell others about it is at the heart of all great businesses. Paul Graham, the legendary investor, puts it simply: “Make things people want.”

The Khushi family have done just this over four generations. Chaudry Mohammed Khushi bought Jacobs & Turner nearly 50 years ago. The firm specialised in workwear and uniforms, including for the local police. In time, it developed a particular specialism in anoraks and waterproof jackets. Its moment arrived with the boom in foreign travel in the 1980s, especially more affordable winter sports. In 1984, Trespass was born with perfect market product fit. It has built a brilliant business on the back of this initial opportunity, always staying close to the customer.

Sometimes, the opportunity is in solving someone else’s market product fit challenge. Working at Kwik-Fit, Mike Welch could see that local garages were getting squeezed out of the tyre-fitting market and, in turn, were losing their bread-and-butter maintenance and repairs business. They didn’t have the buying power or the product range – they looked doomed. Welch turned the challenge on its head with Blackcircles. Having ordered all the Yellow Pages in the UK (imagine the pile), he wrote to every independent garage offering them an online presence and, in time, centralised buying and market-leading data-led marketing.

Blackcircles is one of Scotland’s greatest tech successes but Welch didn’t stop there. He went on to repeat the model for fashion boutiques with Atterley, and move into new markets. Tirebuyer.com is now the biggest player in the US with 11,000 partners.

True market product fit is changing as we change what we value. Increasingly, market fit must also include social and environmental fit. Celia Hodson is an exemplar of combining a commercial social enterprise with profound social and environmental goals. Not only does Hey Girls sell its product through Asda and Waitrose, it is confronting social taboos around period products and environmental waste. It has donated 18 million products back to those in need. Those firms that do not orientate their products to climate and social issues will be the faded stars of the future.

Times are changing, yet there remains a constant. It is all about customers. Get close, learn, experiment. If it doesn’t work out, move on and apply your learning into something new. Who knows that could be the one, so why wait.

Sandy Kennedy, ‘no longer CEO of the Entrepreneurial Scotland Foundation and on a journey’