refers to the physical presence of the customer in a service system

Customer contact

Explanation:

In business, customer contact  can be seen as the physical presence of a customer in a service system.

There are high customer contact services and low customer contact services.

Services with high customer contact include those that there is need for the business to have the physical presence of the customer around the service premises to function better. they include:

Health centers, public transportation, fitness centers, schools and  restaurants

Services with low customer contact include those that there is no need for the business to have the physical presence of the customer around the service premises to function better. they include:

Chemical plants, manufacturing companies.

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a factory opens that mass-produces light bulbs.

explanation:

not sure if that's an answer to your questions but this is an example! : )