Proper modeling can help eliminate the CI and CA splits, which make the application bog down.
Jobs run their fastest, with minimum use of storage capacity, and minimum CPU overhead.
It's easy to compare several alternatives rapidly, and select the best. Production schedules are improved, project test phases significantly shortened. Calculations are included for DASD, tape, and cartridges. There's no need to search for printed cards or other system documentation. Determines Sequential File and Block Size, either for installation or device efficiency, and an make the actual allocation.