With the emergence of the reliable corona rapid tests (result within 10 minutes) the solution is within reach.
Using the rapid tests, you can easily and efficiently detect the employees who do not have any symptoms. However, there is a minor catch. If the test result is negative, it could create a sort of false sense of security inside the company, leading to a disregard for the current corona conduct rules (1.5 metre, hand washing, etc.).
You might be negative today, but tomorrow positive and consequently infecting others.