The phrase 'system upon which' is correct and usable in written English.
It can be used to describe a platform or system that something else is built on top of. For example, "The success of our business is based on the reliable system upon which it is built."
Now Weinreb assaulted the belief system upon which Clarke had staked her career.
The endocannabinoid system upon which marijuana acts is one such system.
This was the system upon which recoilless guns of up to 105 millimetres were developed during World War II.
The approach has been implemented in a feature-rich prototype system upon which testing and evaluation have been conducted.
"Rajaratnam betrayed Galleon's investors, its employees, the counterparties to its trades, and the capital markets system upon which he built his wealth and success," they said.
Similarly angular momentum, which is related to spinning motions, is conserved in a system upon which no net turning force, called torque, acts.
Recent studies in humans have also demonstrated a major role in systemic responses to hypoxia that extends to each of the principal organ systems upon which cellular oxygen delivery ultimately depends.
It is those institutions, after all, that manage and protect the basic payments systems upon which we all depend.
The fact that the quake hit the capital, and demolished every centre of social activity, destroyed the systems upon which daily urban life depends.
We have a government that treats the Earth's systems, upon which our survival depends, as an afterthought, or not a thought at all.
"Churches are respected within communities and most have existing resources, structures and systems upon which to build," he writes of the church in east Africa in his report on faith-based organisations contributing to HIV prevention.
