Expressions and Rules

I have worked across various applications. In my first application, we had 2,3 query rules for same record type but each serving a different purpose depending upon the field being queried or the amount of data being passed. In another project, we have a generic rule for each record type which is being used whenever we want to query the data. In one more project, I have seen only one generic rule being used for all record types which in turn means even the record type is being passed dynamically. I want to understand which approach makes more sense, pros and cons and do we really need to modularize everything this much.

Hi,Here is the scenario I am facing:I open an Expression Rule and implement my logic. I add several test cases to validate the expected behavior. I save the Expression Rule, which creates version 18. Later, I modify the Expression Rule code and save it again, which creates version 19. When version 19 is created, I can see that the test cases from version 18 are available in the new version.Could you please explain why, when I delete version 18 and refresh the latest version, all my test cases are lost?I would expect the test cases to be kept in version 19 since they were automatically carried over when the new version was created.I tried this on many ERs and observed the same behavior.Regards