*   **Gantt Chart:** Visual timeline of process execution. Essential for calculations.
*   **MLQ (Multi-Level Queue):** Multiple queues (e.g., Interactive-RR, Batch-FCFS). Scheduling between queues (Fixed Prio or Time Slice).
*   **MLFQ (Multi-Level Feedback Queue):** Processes move between queues. Aims to favor short jobs & I/O-bound, prevent starvation. (e.g., Q0: RR q=8 -> Q1: RR q=16 -> Q2: FCFS).