The phrase "take over the function" is a correct and usable expression in written English.
It is often used to refer to a situation when one person or group of people assume responsibility for an activity that was previously being done by another. For example, "After the software engineer left the company, his colleague had to take over the function of maintaining the database."
Libraries shouldn't be expected to take over the function of schools.
At this time the middle class also began gradually to take over the function of chief consumer of literature.
In effect, loyal customers not only take over the function of advertising and sales, they even staff the company's help desk for free!
In the 1930s, Gibbon developed the first machine to take over the function of the heart and lungs temporarily, making more invasive surgery possible.
A very smooth reliable pump in a very small form that can be hooked up to your normal vasculature and take over the function of the heart.
Instead, Mr. Mooney fears what he calls green goo: microorganisms that have been manipulated through nanotechnology to take over the function of machines but that begin reproducing out of control.
This restructured assembly would also take over the functions of the UN Security Council which, as Monbiot says, has already largely been sidelined by US actions over Iraq.
The remarkable thing about the brain – especially in someone relatively young – is that healthy parts can learn to take over the functions of damaged areas.
However, as we expect corporations to take over the functions of not only the welfare state but also of humanitarian relief, "freedom as a service" makes perfect sense.
They can stop your heart, your own heart and then this machine will take over the functions of both your heart and your lungs.
We expect teachers to personalise learning rather than teaching everyone in the same mould; we expect them to take over the functions of family.
