MRP stands for material requirements planning. It takes demand (customer orders and forecasts), nets it against the bill of materials and available stock, then tells you what to buy, what to make and when. Good MRP also checks capacity, so the plan can actually run.

In cosmetics and chemicals, the bill of materials is a formula. It changes with approved substitutions, and the stock it draws on has expiry dates, potency and quality status. That's why generic MRP often ends up back in a spreadsheet.

ERP stands for enterprise resource planning. It's the system of record for quotes, customer orders, purchasing, inventory, costing and, usually, finance. Most ERPs include an MRP module, but the depth varies a lot.

• Question it answers. MRP: what do we make and buy, and when? ERP: what have we sold, bought, made and invoiced?
• Main users. MRP: planners and production. ERP: sales, purchasing, finance and operations.
• Key data. MRP: formulas, lots, lead times, capacity. ERP: orders, suppliers, costs, ledgers.
• Where it goes wrong. MRP: planning on stock that's quarantined or expiring. ERP: costs and promises that don't match what production can do.

Almost always. The real question is whether they run as one system or two. When MRP and ERP are separate, someone re-keys orders, checks stock in two places and rebuilds the plan every time a formula or lot changes.

In Worldover, MRP and ERP share one record with R&D, quality and regulatory data. See cosmetics MRP software and chemical MRP software, or cosmetics ERP and chemical ERP. Finance can stay in your existing system or move to Worldover entirely.

MES records what happens on the floor during manufacture. PLM manages formulas, specifications and product changes. In a substance business, all four need the same product and lot data. The more of it lives on one record, the less reconciling your team does.