The phrase "a more rigorous system" is correct and usable in written English.
You can use it when discussing improvements or enhancements to a system that require greater precision, strictness, or thoroughness.
Example: "In order to improve our quality control, we need to implement a more rigorous system for testing our products."
Alternatives: "a stricter framework" or "a more stringent approach".
Undoubtedly, errors remain and a more rigorous system would strengthen these estimates.
A more rigorous system of assessing the riskiness of loans is being foisted upon them.
In the last several weeks, with international help, a more rigorous system for screening, filtering and holding Ebola patients has been instituted.
General Caldwell said the report was based on out-of-date information; the No. 2 American commander in Afghanistan said they were developing a more rigorous system.
In February, Mr. Cuomo used the threat of his emergency budget power to force teachers' unions to accept a more rigorous system of classroom evaluations.
And, they say, the overdoses might have been caught had users followed a more rigorous system of checks and double-checks.
That's one reason some former officials argue that the administration needs to set up a clearer, more rigorous system of internal review — for its own good.
And the governor notched victories on other issues, prevailing on lawmakers to create one of the nation's most expansive databases of DNA samples from criminals, and instituting a new and more rigorous system for evaluating schoolteachers.
Results show that the KC method is capable of replicating the behavior of the more rigorous system, with a good agreement on both the value of maximum tensile forces in the reinforcement and shear and bending moment distributions along the wall.
In a 53-page response to the Laming report, the government said Ofsted, the schools and children's services inspectorate, has designed more rigorous system for regulating safeguarding.
My point here is not to suggest that we should return to a more rigorous grading system (if I do believe that is a good idea), but to observe that, in our current system, A has become a normative grade, and thus no longer a genuine marker of excellence.
