"systems where" is correct and usable in written English.
It is typically used to introduce the conditions that a particular system operates under. For example, "We need to examine systems where the user interface is weak."
Lock in liberal systems where you can.
"There have been some systems where things have gone well.
Arsenic removal systems, where contaminated water if filtered through four chambers, are one available option.
The project focuses on the possibilities of developing systems where plants can be genetically modified.
"Weather systems where they are not supposed to be obvious," he added.
Don't you think all those could look after those welfare systems where they are necessary?
"You're talking about systems where you have unregulated trade at volumes that are significant.
Those benefits are especially important for disadvantaged students in urban systems where dropout rates are high.
In particular, infections can run unchecked in organic farming systems where anthelminthic drug usage is disallowed6.
Surplus was also essential in slave systems where the owners expected economic gain from slave ownership.
Altogether she found 11 genes, in four neurotransmitter systems, where SNPs made a difference.
