SUPPLY PLANNINGLAB

SUPPLY CHAIN DECISION TOOLS

Turn planning data into better decisions.

Free, practical tools for supply planners to model inventory, test assumptions, quantify risk and explain decisions.

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DECISION MODELv1.0
DEMANDSUPPLYCAPACITY
FEASIBLE PLAN
3 inputs2 constraints1 decision
Deterministic calculationsTransparent assumptionsDecision-focused outputs

IMMEDIATE TOOL ACCESS

Start with the planning decision in front of you.

Each lab turns inputs into a calculation, an interpretation, scenarios, and a practical next check.

Safety Stock Lab

Model protection under demand and lead-time uncertainty.

Calculate safety stock

Reorder Point Lab

Determine when to reorder from demand, lead time and protection.

Calculate reorder point

Forecast Accuracy Lab

Diagnose WMAPE, MAE, MAPE, bias and error concentration.

Analyze forecast error

Inventory Health

Translate inventory into DOS, turns, excess and shortage exposure.

Assess inventory

Lead Time Risk

Build and stress-test an end-to-end lead-time assumption.

Stress-test lead time
BETA

Planning Health Check

Find the items driving most forecast, inventory and supply risk.

Run health check

WHY SUPPLY PLANNING LAB

Planner judgment, encoded into practical tools.

Formulas are only the starting point. The useful output is the tradeoff, risk driver, and next decision your team can defend.

Quantify

Turn assumptions into measurable inventory and service impacts.

Stress-test

Compare scenarios before committing inventory or capacity.

Diagnose

Identify the few items driving most planning risk.

Decide

Translate analysis into questions and operational actions.

FEATURED · BETA

Find the few items driving most of your planning risk.

Upload a planning CSV and diagnose data quality, forecast error, bias, inventory exposure and risk concentration. The file is processed locally.

Open Planning Health Check
PLANNING HEALTH72/100
WMAPE24.8%BIAS−8.1%TOP 12 SKU68%
  1. 01Review concentrated forecast error
  2. 02Investigate underforecast bias
  3. 03Rebalance high-DOS items

HOW IT WORKS

From raw inputs to a defensible action.

  1. 01

    Enter assumptions

    Use operational inputs with clearly defined units.

  2. 02

    Calculate

    Deterministic code produces the base metrics.

  3. 03

    Stress-test

    Compare scenarios and identify sensitive drivers.

  4. 04

    Decide

    Translate results into the next operational question.

PRIVACY FIRST

Your planning data stays in your browser.

Core calculations and CSV parsing run on your device. Files are not uploaded to Supply Planning Lab, and operational values are not sent to analytics.

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PLAYBOOKS

Playbooks for real planning questions.

View all playbooks
INVENTORY

How to calculate safety stock without hiding the assumptions

8 min

FORECASTING

WMAPE vs MAPE vs bias: what each metric actually tells you

9 min

INVENTORY

How supply planners should use days of supply

7 min

COMING SOON · $39 LAUNCH PRICE

The Supply Planning Toolkit

A practical workbook pack for forecast accuracy, safety stock, reorder points, inventory health, supplier performance and S&OP reviews.

ABOUT

Built for planners who need to explain the number, not just calculate it.

Supply Planning Lab is an independent project created by Oscar Contreras, a supply chain planning professional and engineer focused on practical decision tools, analytics and AI-enabled planning workflows.

About the project