Sorry, too much question.
I found in a supermarket, the employees sometimes are 28, sometimes are 27, How to add more employees to the supermarket? thanks.
No factory can increase number of employees as is. But you may try deliver there as many people as is possible - to boost consumption.
It is simple - build passengers stop there - and connect that stop into web of buses, trolleybuses or trams. It is all. May it be you would need to use more than one kind of transportation. Because most factories become very important point of interest for people.
I looked into SVN. Shopping mall (that is more beautiful) need 50 people - and supermarket needs 200 people, for full boosting of consumption.