The phrase "a scheme that allowed" is correct and usable in written English.
It can be used when describing a plan or system that enabled a particular action or outcome.
Example: "The new policy introduced a scheme that allowed employees to work remotely, improving overall job satisfaction."
Alternatives: "a plan that enabled" or "a system that permitted".
We developed a scheme that allowed us to manipulate the nanoelectronic to tissue/cell interfaces while monitoring their electrical activity.
Earlier this month, HMRC claimed victory in a four-year battle against Ingenious for a scheme that allowed investors in blockbusters including Avatar to claim tax relief.
In February this year, it announced "EZ-Pass" - a scheme that allowed businesses to upgrade to its BES 12 platform for free, for a limited time.
Labour MP George Mudie accused the governor of recommending a scheme that allowed him and other bank officials to conduct bank rescues in secret and without proper oversight.
Axes Japan played a central role in setting up a scheme that allowed Olympus to keep losses off its books for decades, later settling them in transactions disguised as payments for mergers and acquisitions.
Kim Campbell, 34, who suffers from mental illness and panic attacks, applied for tickets for a music festival in the north-east of England, under a scheme that allowed her to bring her carer on the same ticket.
It's a scheme that allows people to pay for home improvements over time, through their electricity bill.
Here he creates an attention-getting flavor with a yogurt shop owner and devises a scheme that allows a pizzeria to guarantee delivery in eight minutes or less.
Of that, $225m will be redirected to other training programs, including $131m for a scheme that allows private healthcare providers to support undergraduate medical places.
Scientists experimentally demonstrate a scheme that allows the number of qubits encoded per photon to be varied while keeping the overall quantum information constant.
Since 1996 Missouri has pioneered a scheme that allows self-confessed gambling addicts to add their own names to a voluntary blacklist.
