Supply Planning / MRP is where ERP discipline either begins or breaks.
Material Requirements Planning (MRP) Run and Purchase Requisition Generation 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: Component stockout rate below 2%; excess inventory reduction of 10% within 6 months; buyer workload per requisition reduced by 40% through auto-release of low-value replenishment
The control flow a finance team actually needs.
Step 1
Full MRP Regeneration For 100,000...
Step 2
Net-Change MRP Triggered By Individual...
Step 3
Apply Per-Item Lot-Sizing Rules
Step 4
Generate Prioritized Exception Messages
Step 5
Enforce Procurement Approval Thresholds
The ERP surface involved.
Module
Supply Planning / MRP
Actors
MRP Engine, Supply Planner, Procurement Buyer
Tier
Tier 2
Finance area
Supply Chain, Demand Planning & Logistics
Region lens
US and UK finance teams
Publication date
May 15, 2026
Full MRP regeneration for 100,000 component SKUs within 2 hours; support net-change MRP triggered by individual demand or supply events within 10 minutes; apply per-item lot-sizing rules including EOQ, fixed quantity, period order quantity, and min-max; generate prioritized exception messages; enforce procurement approval thresholds; purchase requisitions auto-route based on commodity and spend amount
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 MRP regeneration for 100,000 component SKUs within 2 hours | Given an approved MPS and BOM structure with component inventory, open POs, and planned receipts |
| Control 2 | support net-change MRP triggered by individual demand or supply events within 10 minutes | when the MRP engine runs a full regeneration for component SKUs |
| Control 3 | apply per-item lot-sizing rules including EOQ, fixed quantity, period order quantity, and min-max | then planned purchase orders and production orders are generated applying supplier lead times and lot-sizing rules, exception messages are ranked by priority, and released purchase requisitions route to buyers based on commodity and spend threshold |
| Control 4 | generate prioritized exception messages | negative) when a planner attempts to release a requisition above the approval threshold without authorization then the system must return 403 APPROVAL_THRESHOLD_EXCEEDED. |
| Control 5 | enforce procurement approval thresholds | Component stockout rate below 2%; excess inventory reduction of 10% within 6 months; buyer workload per requisition reduced by 40% through auto-release of low-value replenishment |
| Control 6 | purchase requisitions auto-route based on commodity and spend amount | Component stockout rate below 2%; excess inventory reduction of 10% within 6 months; buyer workload per requisition reduced by 40% through auto-release of low-value replenishment |
Audit evidence is a chain, not a folder.
| Evidence layer | What should be preserved |
|---|---|
| Business event | After MPS approval, the MRP engine explodes the bill of materials for all planned production orders, netting against on-hand inventory, open purchase orders, and planned receipts to calculate component-level requirements. It applies supplier lead times, lot-sizing rules (EOQ, fixed period, min-max), and safety stock to generate planned purchase orders and planned production orders for sub-assemblies. Exception messages are generated for late supply, excess inventory, and reschedule opportunities. Planners review and release planned purchase orders as purchase requisitions, which route to buyers for supplier sourcing. Approved requisitions convert to purchase orders transmitted to suppliers. |
| Control rules | Full MRP regeneration for 100,000 component SKUs within 2 hours; support net-change MRP triggered by individual demand or supply events within 10 minutes; apply per-item lot-sizing rules including EOQ, fixed quantity, period order quantity, and min-max; generate prioritized exception messages; enforce procurement approval thresholds; purchase requisitions auto-route based on commodity and spend amount |
| Acceptance proof | Given an approved MPS and BOM structure with component inventory, open POs, and planned receipts; when the MRP engine runs a full regeneration for component SKUs; then planned purchase orders and production orders are generated applying supplier lead times and lot-sizing rules, exception messages are ranked by priority, and released purchase requisitions route to buyers based on commodity and spend threshold; (negative) when a planner attempts to release a requisition above the approval threshold without authorization then the system must return 403 APPROVAL_THRESHOLD_EXCEEDED. |
| 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_run` { run_id: string, run_type: enum(REGENERATIVE/NET_CHANGE), triggered_at: timestamp, status: enum(RUNNING/COMPLETED/FAILED) }; `planned_order` { order_id: string, run_id: string, item_id: string, order_type: enum(PURCHASE/PRODUCTION), quantity: int64, planned_start: date, planned_receipt: date, lot_size_rule: enum(EOQ/FIXED/POQ/MINMAX), external_id: string }; `mrp_exception` { exception_id: string, order_id: string, type: enum(LATE_SUPPLY/EXCESS/RESCHEDULE), priority_score: numeric }; (reference, product may differ).API and events
`POST /v1/mrp/runs` { run_type, triggered_by_event_id } -> 202 { run_id }; `GET /v1/mrp/runs/{run_id}/planned-orders`; `GET /v1/mrp/runs/{run_id}/exceptions`; `POST /v1/mrp/planned-orders/{order_id}/release` -> 201 { requisition_id }; emits `mrp.run.completed` and `mrp.requisition.created` events; idempotent via `external_id`.State transitions
`PLANNED -> RELEASED`; released becomes `purchase_requisition` with status `PENDING_APPROVAL -> APPROVED -> CONVERTED_TO_PO`; terminal `CANCELLED`; guard: RELEASED blocked if spend exceeds buyer approval limit without escalation approval.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.