Method · Carol Ptak / Chad Smith · Demand Driven Institute · 2011

What is DDMRP —
planning pulled by real consumption.

Demand Driven Material Requirements Planning replaces traditional forecast-based MRP with a pull model: decoupled inventory buffers absorb variability, visual signals (green/yellow/red) prioritize action, and NFP — not the forecast — decides replenishment.

The 5 components of DDMRP

The canonical sequence of the method. Each component feeds the next.

1

Strategic Inventory Positioning

Where do you place the buffers? A strategic decision based on the decoupling point — where demand variability meets supply variability.

2

Buffer Profiles & Levels

Each SKU has a profile (item type × lead time × variability) that defines dynamic levels: red zone (safety), yellow zone (lead time coverage), green zone (lot/frequency).

3

Dynamic Adjustments

DAFs (Demand Adjustment Factors) adjust the buffer for seasonality, trend or events. Black Friday, harvest, planned promotion — buffers grow or shrink automatically.

4

Demand Driven Planning

Net Flow Position = on-hand + on-order − qualified demand. NFP enters the yellow zone → suggests replenishment. Red → urgency. No more MRP runs on every forecast.

5

Visible & Collaborative Execution

Open orders prioritized by buffer color. The team sees in real time which SKU needs attention — no more weekly 'where's my product' meetings.

3-zone buffer

The intelligence of DDMRP in a single picture.

Green Zone — Top of Green (ToG)

Order frequency and lot size. Buffer is "healthy" — nothing to do.

Yellow Zone — Top of Yellow (ToY)

Lead time coverage (ADU × DLT). NFP enters here → system suggests replenishment.

Red Zone — Top of Red (ToR)

Safety against variability. NFP enters here → urgent, prioritized in execution.

Below Red

Real stockout risk. Immediate action, escalation.

Net Flow Position (NFP)

The formula that decides replenishment:

NFP =
+ On-hand (current stock)
+ On-order (in process)
− Qualified Demand (qualified demand)

Qualified Demand includes: accumulated daily demand (next 24h), past-due orders, qualified spikes (Order Spike). NFP is recalculated several times a day.

Traditional MRP vs DDMRP

Why the forecast is no longer the only anchor of planning.

Aspect Traditional MRP DDMRP
Replenishment signal Demand forecast Real buffer consumption (zones)
Calculation frequency Full MRP run (weekly/daily) Continuous NFP calculation per buffer
Response to variability Full replan, MRP nervousness Buffer absorbs, plan stays stable
Lead time Fixed lead time per item Decoupled Lead Time (DLT) per buffer
Visual signal Exception lists, spreadsheets 3-color buffer (green/yellow/red)
Stockout resilience Emergency replan Buffer was sized to absorb it
Forecast reliance Critical — bad forecast breaks plan Low — buffer pulled by consumption
Where it works Predictable flow, stable demand High variability, complexity, multi-level

When DDMRP fits (and when it doesn't)

Honesty is worth more than selling the wrong method.

When DDMRP makes sense

  • 1,000+ active SKUs with erratic or seasonal demand
  • Deep BOMs (multi-level) with shared critical components
  • Long or volatile lead times (imports, single-source suppliers)
  • Multi-warehouse, multi-plant operations with internal transfers
  • Production planning currently based on spreadsheets + weekly exception meetings
  • Finance team feeling pain with WIP (inventory stuck in process)

When DDMRP doesn't make sense

  • ! Operation with <100 SKUs and stable demand — simple MRP is enough
  • ! Pure engineer-to-order business with no repetition
  • ! No structured production planning team — DDMRP requires execution discipline
  • ! Simple supply chain with no unstable suppliers — there is no variability for the buffer to absorb

DDMRP glossary

The 12 terms that come up in any buffer conversation.

ADU Average Daily Usage

Average daily usage of an SKU. Calculated from history (past), forecast (future) or blended (combined).

DLT Decoupled Lead Time

Effective lead time considering upstream buffers. Shorter than the cumulative lead time.

NFP Net Flow Position

On-hand + On-order − Qualified Demand. The metric that decides whether a buffer needs replenishment.

ToG Top of Green

Top of the green zone — the buffer's maximum level.

ToY Top of Yellow

Top of the yellow zone — below this, replenishment signal.

ToR Top of Red

Top of the red zone — below this, urgency.

DAF Demand Adjustment Factor

Factor that multiplies ADU within a date window — seasonality, event, trend.

BP Buffer Profile

Combination of item type × lead time × variability that defines how the buffer is sized.

MOQ Minimum Order Quantity

Supplier minimum order quantity. Influences the green zone.

OST Order Spike Threshold

Threshold that defines a concentrated demand spike — generates anticipated qualified demand.

DDOM Demand Driven Operating Model

Layer above DDMRP — synchronizes production with Drum-Buffer-Rope, control points and time buffers.

PFI Part Flow Index

A metric of part flow through the chain — how long an item spends between buffers.

Frequently asked questions

Is DDMRP really better than traditional MRP?

It depends on the context. Traditional MRP works when demand is predictable and supply is stable. In environments with high variability (imports, seasonality, erratic demand), DDMRP delivers fewer stockouts and less stagnant inventory. Companies with 1,000+ SKUs and complex supply chains typically reduce inventory by 20–50% when they migrate.

Who invented DDMRP?

Carol Ptak and Chad Smith published it in 2011 in the book 'Demand Driven Material Requirements Planning'. The Demand Driven Institute (demanddriveninstitute.com) certifies professionals and companies that apply the method.

Does DDMRP exist in Odoo?

Yes. ForgeFlow (Spain) developed a complete stack: 24 modules published on OCA (LGPL-3, free) covering the DDMRP core, plus 50+ premium 'Professional' modules covering dashboards, multi-level simulation, freight optimization, DDOM and more. KMEE is the official ForgeFlow partner for DDMRP Enterprise in Brazil.

How fast do you see results?

Technical diagnosis: 2–4 weeks. Buffer profile setup: 4–6 weeks. Pilot on 1 product family: 4–6 weeks. Roll-out to all SKUs: 8–16 weeks. Total ~4–6 months to stabilize and see inventory reduction + stockout reduction.

Does it work alongside the Brazilian fiscal localization?

Yes — that's KMEE's differentiator. ForgeFlow's DDMRP stack integrates natively with OCA l10n-brazil (NF-e, NFS-e, fiscal, CNAB) on the same Odoo database. There is no ETL, no system-to-system synchronization. Buffers, orders, purchase orders and fiscal documents all live in the same data model.

Is the Professional stack expensive?

You can start with the free OCA layer and add Professional/Enterprise modules as you mature. KMEE provides a price range during diagnosis, considering: ForgeFlow licenses (negotiated through the official partnership), KMEE implementation, and optional DDI training for the planning team.

Where can I learn more?

We recommend: (1) the book 'Demand Driven Material Requirements Planning' — Ptak/Smith (2011); (2) the Demand Driven Institute (demanddriveninstitute.com); (3) the ForgeFlow blog (forgeflow.com); (4) the OCA/ddmrp GitHub repo; (5) your next KMEE diagnosis session.

Want to apply DDMRP in your Odoo?

KMEE is the official ForgeFlow partner for DDMRP Enterprise in Brazil. Free 30-minute diagnosis to map your scenario.