Planning (MRP)
How demand turns into suggested jobs and purchase orders — and where that ends and scheduling begins.
Planning answers one question: what should we make or buy, and how much? Carbon's looks at everything you owe and everything you have coming, and turns the gap into suggested orders that you choose to act on.
Without planning you'd reorder by hand. MRP nets demand against supply across the whole , so a shortfall on a top-level robot surfaces as the right quantity of every component, offset for its — before you're caught short.
Two stages
Planning runs in two distinct passes, and conflating them is the usual mistake:
- MRP, explode and net. The engine explodes demand through bills of material, nets it against on-hand plus open jobs and purchase orders, and writes period-bucketed demand forecasts (plus the demand and supply actuals it read). It does not apply and does not create orders.
- Planning views, suggest a quantity. The production and purchasing planning pages read those forecasts, project running stock week by week, and apply each item's to propose a quantity to order.
MRP suggests, it never auto-orders. The engine only writes forecasts; turning a suggestion into a real job or PO is an explicit action you take on the planning page.
What feeds it
| Input | Source |
|---|---|
| Customer demand | Open sales-order lines, by promised date. |
| Production demand | Job material still to issue, offset by lead time. |
| Forecast demand | Manually entered demand projections. |
| Open supply | Open jobs and open purchase-order lines. |
| On hand | The item ledger balance. |
Reorder policy
Each item, per location, carries a reordering policy that decides how a suggestion is sized: Manual Reorder (suggests nothing), Demand-Based Reorder (the default), Fixed Reorder Quantity, or Maximum Quantity. Each is tuned by reorder point, order quantity, accumulation period, and min/max/multiple rounding. See Reordering for the parameters in full.
From suggestion to order
An item's routes where its shortfall shows up: Make items surface on the production planning page as suggested , Buy items on the purchasing page as suggested POs. Choosing Order creates a real job or purchase order at status "Planned" — persisted from planning, but not yet released into the normal lifecycle.
"Planned" is a real, saved job or PO that came from a planning suggestion and is waiting to be released — distinct from a hand-started "Draft".
Planning vs scheduling
Planning decides what and how much; scheduling decides when and where. Once a job exists, the scheduling engine places its onto and computes their dates — it never changes quantities. The two are separate subsystems that meet at the job: planning finalizes it, scheduling sequences it onto the floor.