The owner of a firm said to the employees (there is no one manager in this firm, every one can run the company)., do you think this method works?

No, I don't think so. Someone has to undertake to leadership. Someone has to co-ordinate the employees and someone has to take decisions.Probably the one who said that wasn't commited to the manager's job or he said that in order to be liked by his employees and to create the illusion that every job is equal to another one. I think that with this quote he underestimates the logic of his employees! 

Actually this suggestion will create chaos in the company. Let us say everybody is a manager but who will take a decision, who will represent the company, go to court in case of problems, sign in name of the company...It is simply irrational.

While on the other hand it would be normal for a firm owner to say that none of the employees is a manager.

Never! The company must have structure and organization. The management should take the responsability to give the all day duties to the employees.

Without any of these elementary things, no company will be successful!

For a commision based job, the idea will work because everyone will be challenged to work extra hour to get a better pay, knowing they are their own manager... But for a monthly paid job, it is a no idea, because no one will be willing to work knowing that no one is taking any responsibility....