Replenishment exists in two tempers, and the difference between them is the difference between the Planning and Advanced tiers (5.11).
Planning: the worklist advises. With Planning on, every product-and-warehouse pair can carry planning parameters: a reorder point, lead times, safety cover, order quantities. The reorder point is computed for you — average daily demand over your demand window, times the lead time, plus safety stock for the days things run late — and shown beside any manual point you set; a manual point always wins and is never overwritten by the computation. The Replenishment worklist (§5.10) lists every pair whose projected quantity — on-hand, plus on-order, minus committed — has fallen to its reorder point, with the quantity suggested, the date it is needed by, and a hint from experience: how long this supplier actually took on recent deliveries, not just what they promised. Not buying yet? Dismiss with a reason, and the row sleeps for the days you set instead of nagging daily.
Advanced: the worklist drafts. With Advanced on, the same worklist gains two actions: Generate draft purchase orders and Generate draft work orders. Rows for things you buy group into one draft purchase order per supplier, priced from the catalogue, ready for a human to review, approve and send; rows for things you make become draft work orders against their bill of materials (Chapter 10). Generation is careful about one thing above all: it never duplicates. Quantities already sitting on an open draft count as coverage, and only the uncovered remainder is drafted; a row it cannot act on is skipped by name, with its reason — no default supplier set, say — never silently. Nothing is approved or posted for you: the drafts are ordinary documents, and the judgement stays with the people.