The phrase "an existing system" is correct and usable in written English.
You can use it when referring to a system that is currently in place or operational.
Example: "The new software will integrate seamlessly with an existing system to enhance overall efficiency."
Alternatives: "a current system" or "an active system."
"Bizdom isn't catalyzing an existing system; it's trying to create something almost from scratch," he said.
Mr Balls argued that building on an existing system would be "a more straightforward proposition".
"It's not an easy task to uproot an existing system, no matter how bad, with a new one," he argued.
"We're talking about an existing system already in place that meets a lot of India's existing requirements".
From there, an existing system of pumps, canals and aqueducts will deliver the water to Los Angeles, Silicon Valley and millions of acres of farmland in central California.
The proposal mirrors an existing system of user fees paid by drug companies for speedier reviews of medications by the food and drug agency.
But with an existing system encouraging chief executives to take decisions solely on their profitability, even in the richest countries inequality is increasing.
By offloading the responsibility for problem solving from governments to citizens, self-tracking can get us to optimize our behavior within the constraints of an existing system.
But let's not conflate political and social entrepreneurship: one works in an existing system; the other rejects the prevailing system to create something new and more effective.
That bit isn't for novices, but anyone who has an existing system that likely took a bit of work to set up will probably be able to do it.
But segregationist zeal did not flare in a vacuum; it built on an existing system of allocating space which reflected the needs of an imperial elite.Those needs were complex and shifting.
