Planning / MRP is where ERP discipline either begins or breaks.
Material Requirements Planning (MRP) Run & Action Message Processing looks operational from far away. In a real finance team, it is a chain of assertions: the right actor started the work, the required records existed, the control policy was applied, the state change was preserved, and the outcome can be explained later without rebuilding the transaction from emails and spreadsheets.
The expected business outcome is specific: Material shortages are identified weeks in advance; planner workload shifts from expediting to exception management; purchase order and work order release is driven by actual demand rather than manual estimation.
The control flow a finance team actually needs.
Step 1
Full-Regenerative And Net-Change MRP Modes
Step 2
Low-Level Code Calculation For Correct...
Step 3
For All Standard Lot-Sizing Rules
Step 4
Safety Stock And Safety Lead Time
Step 5
Pegging From To Source
The ERP surface involved.
Module
Planning / MRP
Actors
MRP Planner, Purchasing Agent, Production Scheduler, ERP System
Tier
Tier 2
Finance area
Manufacturing & Production
Region lens
US and UK finance teams
Publication date
May 6, 2026
Full-regenerative and net-change MRP modes; low-level code (LLC) calculation for correct explosion sequence; support for all standard lot-sizing rules (lot-for-lot, EOQ, fixed order quantity, period order quantity); safety stock and safety lead time; pegging from requirement to source (demand-to-supply trace); action message workbench with filter/sort/bulk-firm; planner code routing; MRP simulation mode (what-if without committing); runtime < 15 minutes for 50,000 active items on standard hardware; ATP/CTP calculation post-run.
US and UK teams have different compliance hooks, but the same control problem.
US teams usually care about clean evidence for audit support, vendor records, payment controls, tax reporting, and management review. UK teams usually care about VAT-ready records, approval evidence, digital-record discipline, and traceable postings. The country-specific details differ, but the operating pattern is the same: the ERP needs controlled records, explicit ownership, defensible state changes, and evidence that survives beyond the person who completed the task.
The control matrix.
| Control area | Requirement | Acceptance proof |
|---|---|---|
| Control 1 | Full-regenerative and net-change MRP modes | Given an approved MPS and open inventory/PO/WO records |
| Control 2 | low-level code (LLC) calculation for correct explosion sequence | when an MRP planner triggers a full-regenerative run |
| Control 3 | support for all standard lot-sizing rules (lot-for-lot, EOQ, fixed order quantity, period order quantity | then the system returns run_id with action messages of types NEW_ORDER, RESCHEDULE_IN, RESCHEDULE_OUT, CANCEL each referencing demand and supply records |
| Control 4 | safety stock and safety lead time | negative) when a planner attempts to firm a planned order for an item where the LLC has not been calculated then 422 LLC_NOT_CURRENT. |
| Control 5 | pegging from requirement to source (demand-to-supply trace | Material shortages are identified weeks in advance; planner workload shifts from expediting to exception management; purchase order and work order release is driven by actual demand rather than manual estimation. |
| Control 6 | action message workbench with filter/sort/bulk-firm | Material shortages are identified weeks in advance; planner workload shifts from expediting to exception management; purchase order and work order release is driven by actual demand rather than manual estimation. |
Audit evidence is a chain, not a folder.
| Evidence layer | What should be preserved |
|---|---|
| Business event | The planner triggers a full-regenerative MRP run, which explodes the MPS and open sales orders through all BOM levels, netting gross requirements against on-hand inventory, open purchase orders, and existing work orders. The system generates action messages: new planned orders, reschedule-in, reschedule-out, and cancel recommendations. The planner reviews the action message workbench, filters by exception type and buyer/planner code, and firm-converts planned purchase orders to requisitions (routed to purchasing) and planned production orders to firm work orders (routed to scheduling). Firmed orders are removed from the next MRP action message set. |
| Control rules | Full-regenerative and net-change MRP modes; low-level code (LLC) calculation for correct explosion sequence; support for all standard lot-sizing rules (lot-for-lot, EOQ, fixed order quantity, period order quantity); safety stock and safety lead time; pegging from requirement to source (demand-to-supply trace); action message workbench with filter/sort/bulk-firm; planner code routing; MRP simulation mode (what-if without committing); runtime < 15 minutes for 50,000 active items on standard hardware; ATP/CTP calculation post-run. |
| Acceptance proof | Given an approved MPS and open inventory/PO/WO records; when an MRP planner triggers a full-regenerative run; then the system returns run_id with action messages of types NEW_ORDER, RESCHEDULE_IN, RESCHEDULE_OUT, CANCEL each referencing demand and supply records; (negative) when a planner attempts to firm a planned order for an item where the LLC has not been calculated then 422 LLC_NOT_CURRENT. |
| Data record | |
| System event | |
| Lifecycle state | |
The useful version of this workflow is not only fast. It is inspectable. A controller, auditor, or operator should be able to move from source event to system record to state transition to final business outcome without guessing.
Implementation contracts.
Reference data model
`mrp_runs` { run_id: string, run_type: enum, started_at: timestamp, completed_at: timestamp, status: enum }; `mrp_action_messages` { message_id: string, run_id: string, item_id: string, action_type: enum, suggested_qty: numeric, suggested_date: date, planner_code: string, external_id: string }; (reference, product may differ).API and events
`POST /v1/mrp/runs` { run_type: FULL_REGENERATIVE|NET_CHANGE } -> 202 { run_id }; `GET /v1/mrp/runs/{run_id}/action-messages` with filter params; `POST /v1/mrp/action-messages/{message_id}/firm` -> 200 { planned_order_id }; emits `mrp.run_completed` event; idempotent via `external_id`.State transitions
`PENDING -> RUNNING -> COMPLETED`; terminal `FAILED`; action messages: `OPEN -> FIRMED -> CANCELLED`; guard: FIRMED removes message from next MRP action set.Common implementation traps.
Treating the workflow as data entry
If the ERP only stores the final record, the team loses the decision trail that explains how the record became valid.
Hiding exception logic
Exceptions need owners, reason codes, and time stamps. A vague pending state is not a control.
Posting without recovery design
Retries, duplicate submissions, and partial failures must be explicit so the system does not create inconsistent records.
Skipping evidence design
A workflow that cannot produce evidence on demand will eventually push finance teams back into manual screenshots and spreadsheets.
Where Rivane fits.
Rivane is built for finance workflows where automation must stay tied to source documents, approvals, state transitions, ledger impact, reporting, and audit evidence. Use this guide as a checklist for evaluating whether an ERP workflow is merely digitized or actually controlled.
References and source basis.
These sources provide the standards, regulatory, or government context around the flow. They are included so the guide is useful to finance operators, auditors, and implementation teams, not only buyers reading software copy.