Answer:
These are two different methods for calculating the required longitudinal reinforcement.
Factorizing Provided Reinforcement
The entire provided longitudinal reinforcement (compression and tension reinforcement) is equally scaled with a factor. This means that the reinforcement in the compression and tension zones has the same factor.
Optimizing Provided Reinforcement
The provided longitudinal reinforcement is divided into upper and lower reinforcement (compression and tension reinforcement), and is scaled with different factors. This option allows you to scale only the required tension reinforcement accordingly, while any unrequired reinforcement in the compression zone is set to zero.
