The phrase "a system which is" is correct and usable in written English.
It can be used to describe or define a particular system and its characteristics or functions.
Example: "We are developing a system which is designed to improve efficiency in our operations."
Alternatives: "a system that is" or "a system which has".
That is a system which is actually working against the kids having two parents around".
"In a nonunionized setting, they are working within a system which is not of their design," she said.
"We want a system which is fair to everyone involved so that debt problems don't spiral out of control".
We need a system which is quicker, and provides greater certainty for local firms and local residents.
Chris Giles in the FT (paywall) is - inevitably - very good on the economics of "dynamic scoring", a system which is favoured by right wing politicians but already controversial.
Twenty-two percent of Rotterdam's containers are now shipped through such a system, which is intended to ease congestion on roadways by using more water and rail routes.
European allies, as well as Russia and China, have opposed the development of such a system, which is forbidden by the 1972 Antiballistic Missile Treaty signed with Moscow.
The campaign focuses on modernising the city's politics, he says, and dragging them out of a system which is based in the 19th century.
"We have discovered a system which is very similar to Tangentopoli, involving characters who were involved back then, but much more complex and sophisticated".
"The parents can be forgiven for thinking that they are trapped in a system which is neither compassionate nor even humane.
But to adopt a system which is fundamentally flawed and then create all manner of institutions to prevent its inevitable collapse is bonkers.
