When you are calculating an ERUF value, some sections of code will require you to estimate. For example, if the entry logic in a transaction had the following RDML commands:
SELECT FIELDS(.....) FROM_FILE(.....) WITH_KEY(....)
then you will have to realistically estimate how many records the select loop will find and add to the list. If you estimate 20, then this will add 2.0 to your entry logic ERUF value, which will probably keep the transaction in the simple range.
However, if the reality is that 500 will be added, then this will add 50.0 to your ERUF value, pushing the transaction well into the very complex range.
The importance of this effect is sometimes overlooked when creating applications, but the reality is that for this particular piece of RDML code, the second version does 25 times more work than the first - even though it does not look to be 25 times more "complex".