But, the Pasupa bothers and sister think that is old school and simply not true. Together, they run the Soontra fruit- and herbal-drinks company.
The two-brothers-and-sister team find operating the company together brings them closer.
"We have more time to talk. We meet more often. And, we talk about more things than before," says sister, production and factory manager and youngest Chulinthorn Pasupa.
Surin Pasupa, the younger brother, says working with his siblings is a positive thing.
"We make decisions faster and dare to use trial and error. In some situations we can talk at night and get the ideas into play the very next morning. It's good for business," he says.
Mother Supanna Soontrapa was the inspiration behind the business. Seven years ago she was making drinks for the family. They were well liked and in big demand.
Brothers Supat and Surin decided the beverages might appeal to more than just family members. So, in 2002 they decided to give it a try.
Five years on they have proved family and business do mix.
Starting from nothing, it is now a 60-outlet concern with branches all over Bangkok - at many department stores and almost every Skytrain station.
It plans to expand to Nakhon Pathom and Ratchaburi. The siblings' goals are endless.
"There are factors challenging us all the time. Everyday is fun ... not too serious. The business is stable and at the top - that should be enough. But, I realise we have to step forward and continually develop," manager and eldest Supat says.
Each business day brings situations not found in the textbooks or taught in MBA lectures.
"Many things are written about this and that and about how to achieve sales. But, we have had to learn from our mistakes," Supat says.
"Experience teaches you to do things with the fewest problems."
Even though their work is now confined to administration the three still get out and talk to customers for feedback.
This kind of market research has seen more drinks' variety. The three have developed seasonal drinks and artist ML Chirathorn Chirapravati, known to many simply as Ajarn To, has advertised gift sets.
"Customers are interested in new things. If we don't offer them new things the competition will take our customers away," Supat says.
Soontra drinks are marketed as healthy. Every new product is considered for its nutritional value.
"We launch new products to offer customers variety in nutritional drinks. One drink might be a source of vitamin C and another A," Supat says.
Soontra targets the "new generation" and working-people. Its kiosks are all white to show cleanness. Packaging is modern.
"We pay attention to design and image to create a difference and also serve customer lifestyles," Surin says. He was in creative design before entering the beverage game.
All three siblings worked for other companies before starting Soontra and so have management experience.
Today they all wear two hats - at work and at home.
"We have to divide our work and personal lives. If we have a work argument it comes to an end at the end of the meeting.
"When we step out of the office, we are family," Surin says.
By Suwicha Chanitnun