The phrase "systematically used" is correct and can be used in written English.
It means something that is used in a methodical and organized manner. Example: In science experiments, data is systematically used to draw conclusions and support hypotheses.
He also said there is no evidence that the privacy of ordinary Italians was violated by Italian or foreign intelligence activity, and that US authorities have assured him that intelligence gathering has not been "systematically" used against Italy.
Thousands of women were jailed and systematically used as sex slaves until they became pregnant.
In Europe during the Middle Ages, intelligence was systematically used but crudely organized.
Then the items in those lists are systematically used to create triggers for creative solutions.
Since September 11th, Roth added, the military has systematically used third-degree techniques around the world on detainees.
Peremptory challenges, where lawyers strike potential jurors without stating a reason, are systematically used to distort jury demographics.
But for much of the ensuing 40 years, he was confronted, even haunted, by the tactics of torture systematically used in Algeria.
Sulfa drugs were the first chemical substances systematically used to treat and prevent bacterial infections in humans.
Merit indices and merit exponents are systematically used to solve the material optimisation problem.
Simultaneously, ISPs systematically used lawsuits to chip away at the legal foundations of net neutrality protections so that by 2014, only Title II was left standing.
These guidelines can be systematically used along with evaluation methods to reason about design considerations and tradeoffs.
