Demand Supply Planning Tools: 2026 Buyer's Guide

Short answer: Demand supply planning tools do two jobs. Demand planning estimates what customers will buy, by SKU and by week or month. Supply planning turns that estimate into purchase orders, production and stock moves, within real limits such as supplier lead times, minimum order quantities, cash and capacity. Shopify brands usually need a replenishment app that does both for finished goods. Manufacturers need a tool that also plans raw materials through a bill of materials. Larger multi-site businesses need a planning suite that weighs capacity and materials together.

Last updated: November 2026

Disclosure: Forthsuite publishes this guide and also builds Forthcast, one of the tools listed below. Tools are grouped by type, not ranked.

Demand planning vs supply planning: what each tool does

Demand planning answers "how many will we sell, and when?" A demand planning tool reads sales history, adds seasonality and trend, and produces a forecast per SKU over a horizon. Good ones show the history and assumptions behind each number so a planner can check it. For the methods behind those numbers, see demand forecasting: definition and methods.

Supply planning answers "what do we need to order or make, and by when, to meet that forecast?" A supply planning tool compares the forecast with stock on hand and stock already on order, then proposes purchase orders, production orders or transfers. It has to respect the limits of the real supply chain: how long a supplier takes, the smallest order they accept, how much cash is available and, for a factory, how much it can produce.

Many products do some of both. The useful question is where each product stops. Some stop at a forecast chart. Some recommend a reorder quantity. Some draft a purchase order for you to review. Planning suites can rebalance a whole network of plants and warehouses.

"I would definitely love something automated like we're in 2026. I can't believe I still have to do an export of my sales from Shopify, do an export of the stock … at the 3PL." Global Director Ecommerce at a US luxury skincare brand (Forthsuite merchant research interview, March 2026; name withheld).

How to choose a demand and supply planning tool

Choose by the decision the tool must make after the forecast, then check five things.

1. Data sources

List where your demand and stock data live today: the store (for example Shopify), marketplaces, wholesale orders, a 3PL or warehouse system, and an accounting or ERP system that holds purchase orders. The tool should read each of these directly. If it needs a weekly CSV export, you keep the manual work you are trying to remove. Ask how it treats returns, cancelled orders, bundles and stock that was out of stock (lost sales look like zero demand unless the tool corrects for them).

2. Constraints: lead times, MOQs and cash

A forecast is not an order. The order has to fit the supplier. Check whether the tool lets you set a lead time per supplier or per SKU, a minimum order quantity, case or carton multiples, and a budget. Then check what it does with them: does it round the quantity up to the MOQ, warn you, or ignore it? Ask the vendor to show a real recommendation that changed because of a lead time or MOQ. For how to measure the lead time you enter, see our lead time guide.

3. Inventory and purchasing visibility

To plan supply, the tool must see more than stock on hand. It needs stock committed to open orders, stock on open purchase orders, stock in transit and stock at each location or 3PL. Ask how often each source syncs. "Real-time" in a demo can mean an hourly or daily sync in practice, which is fine for weekly buying but matters if you sell through stock fast.

4. Integrations and output

Check where the result goes. A purchase order that stays inside the planning tool may still need retyping into your ERP, accounting system or supplier email. Ask whether purchase orders sync back, and who approves them before they go out.

5. Fit and total cost

Match the tool to the size of the operation. Count every fee: per SKU, per order, per location, per user, onboarding and annual contracts. Then run a pilot on a sample of steady, seasonal, new and slow-moving SKUs and compare the tool's suggestions with what your team would have ordered.

Which tools build constrained order plans that respect lead times?

Most planning tools use lead time to decide when to reorder. Far fewer build a full plan that respects several limits at once. In practice there are three levels:

• Reorder recommendations with lead time and MOQ inputs. Commerce replenishment apps calculate when stock will run out, subtract the supplier lead time, and suggest a quantity. Some let you set MOQs and case sizes; check that in a trial, because the pricing pages we read rarely spell it out.
• Material requirements planning (MRP). Manufacturing tools explode a production plan through a bill of materials into raw material purchase orders, each with its own lead time. Katana and GMDH Streamline both describe BOM or MRP features on their sites.
• Constraint-aware network planning. Enterprise suites plan demand, supply, inventory and capacity together and let planners compare scenarios. Kinaxis, RELEX and ToolsGroup sit here. Expect a longer implementation and quoted pricing.

Whatever the level, an automatic plan should still stop at a clear approval step. A tool that drafts the order and lets a person approve it is easier to trust than one that places orders on its own.

Which tools give visibility into inventory and purchasing?

Look for one screen that shows, per SKU: on hand by location, committed, on order with expected arrival date, and forecast demand over the lead time. Prediko and Inventory Planner both describe multi-warehouse or multi-store views and purchasing recommendations; Netstock and GMDH Streamline read stock and purchase orders from the ERP; Kinaxis describes combining "real-time data from across your supply chain into a single platform". Confirm the sync frequency for your own systems before you rely on any of them.

Shopify brands vs manufacturers: who needs what

Shopify and direct-to-consumer brands

You buy finished goods from suppliers and sell through Shopify, perhaps with Amazon, wholesale or a 3PL. You need a SKU-level forecast from Shopify order history, reorder points and safety stock, supplier lead times and MOQs, and draft purchase orders. A Shopify-connected replenishment app usually covers this without an ERP project. Our guide to inventory forecasting methods for Shopify merchants explains the calculations these apps run.

Manufacturers

You turn raw materials into finished goods, so a finished-goods forecast is only the start. You need a bill of materials, production orders, raw material purchase orders with their own lead times, and some view of capacity. Small and mid-size manufacturers often start with a manufacturing inventory system such as Katana, or a planning layer on top of their ERP such as GMDH Streamline or Netstock. Multi-plant manufacturers move to suites such as Kinaxis or ToolsGroup.

Retail chains and distributors

Many stores or warehouses add allocation and transfers between locations. RELEX and ToolsGroup both describe retail and wholesale planning; Inventory Planner describes store and warehouse transfers for smaller multi-location retailers.

Demand and supply planning tools by type (checked 7 November 2026)

Each entry uses only what the vendor's own site said on the page named, on 7 November 2026. Where no price is published, we say so rather than guess. Within each group, tools are listed alphabetically, with our own product last.

Replenishment apps for Shopify and ecommerce brands

Tool	What its site says it does	Integrations named	Pricing (as published)
Inventory Planner (by Sage)	Forecasting, purchasing recommendations, multi-warehouse planning, warehouse and store transfers	Shopify and Shopify Plus, Amazon, WooCommerce, eBay, NetSuite, QuickBooks, Cin7, Brightpearl, Linnworks, Microsoft Dynamics 365, ShipHero	Not published; quote on request
Prediko	Shopify app for D2C brands: AI inventory forecasting, purchase order management, multi-store and warehouse; raw materials forecasting and BOMs as an add-on	Shopify, Shopify POS, Shopify B2B, Amazon, TikTok Shop, Walmart, "150+ WMS, eCommerce platforms and 3PLs"	Tiered by annual GMV: from $49 a month (under $100K GMV) to $3,999 a month ($45M to $50M); contact sales above $50M; lower annual rates; 14-day free trial
Forthcast (ours)	Shopify app: store-wide forecasts up to 12 months ahead, reorder recommendations you check against supplier lead times, cash budget and minimum-order requirements, draft purchase orders for review; does not place orders or run transfers between locations	Shopify	$19.99 a month, one plan, no per-SKU fees, 14-day trial billed through Shopify

Planning layers for ERP-based businesses and manufacturers

Tool	What its site says it does	Integrations named	Pricing (as published)
GMDH Streamline	Demand forecasting, inventory planning, replenishment and purchasing, S&OP; its site says it runs "S&OP and MRP across NetSuite, SAP, and 30+ ERPs"; aimed at medium and large companies	NetSuite, SAP and SAP Business One, Microsoft Dynamics 365 Business Central, QuickBooks, Odoo, Cin7, Extensiv, Finale and others	Not published; customised pricing on request
Katana	Manufacturing and inventory: multi-level BOMs, manufacturing orders, purchase orders; demand planning, forecasting and replenishment planning on the paid plan	Shopify, QuickBooks, Xero and others	Free plan for up to 30 SKUs; Advantage plan at custom pricing on an annual contract
Netstock	Demand and supply planning software connected to the ERP	NetSuite, Acumatica, SAP Business One, Microsoft Dynamics, Sage (including Sage X3 and Sage 200), SYSPRO, MYOB, Cin7 Core, Unleashed and others	"Pricing starts at $900/month"; exact estimate via a form

Enterprise planning suites

Tool	What its site says it does	Who it names	Pricing (as published)
Kinaxis (Maestro)	Supply planning, demand planning through to logistics orchestration; "concurrency" and unlimited scenario modelling	Supply chain leaders	No price on the pages checked
RELEX	Forecasting, automated replenishment, end-to-end supply chain planning, plus merchandising and assortment planning	Retailers, manufacturers and wholesalers	No price on the pages checked
ToolsGroup	Probabilistic demand forecasting, multi-echelon inventory optimisation, S&OP and integrated business planning	Aftermarket parts, manufacturing, food and beverage, wholesale distribution, retail	No price on the pages checked

Prices and features change. Check the vendor's page before you buy, and ask each vendor to show your own SKUs in a trial or demo.

Forecasting-only software vs replenishment software

Choose forecasting-only software when the main job is modelling demand and another system already owns purchasing. Choose replenishment software when the problem is deciding what to reorder, when, and how much, and turning that into a purchase order. If you use both, decide which system owns the forecast and which owns the final order.

How to run a pilot

1. Write down the current process: every export, spreadsheet, approval and email.
2. Pick 20 to 50 SKUs that include steady, seasonal, new, slow-moving and intermittent items.
3. Connect sales, stock, open purchase orders, supplier lead times and MOQs.
4. Compare the tool's suggested orders with what your team would have ordered, and look into the large differences.
5. Decide who approves orders and how exceptions are handled.
6. Measure forecast error and stockouts on a fixed schedule. Track bias as well as accuracy so over- and under-forecasts do not cancel out.

Two short definitions help when you read vendor material: demand forecasting, and demand variability, which drives how much safety stock a tool will suggest. If the vendor talks about reacting to very recent signals, that is demand sensing; our guide to demand sensing solutions for ecommerce compares those options.

Frequently asked questions

What is the difference between demand planning and supply planning?

Demand planning estimates what customers will buy. Supply planning decides what to buy, make or move to meet that demand, within lead times, order minimums, cash and capacity.

What are the best demand and supply planning tools?

It depends on the business. Shopify brands buying finished goods usually fit a replenishment app such as Inventory Planner or Prediko. ERP-based companies and smaller manufacturers often add Netstock, GMDH Streamline or Katana. Multi-site enterprises look at Kinaxis, RELEX or ToolsGroup.

What are the best demand forecasting tools for manufacturing?

Manufacturers need forecasting connected to a bill of materials and raw material purchasing. Katana and GMDH Streamline describe BOM or MRP features; larger manufacturers use suites such as Kinaxis or ToolsGroup.

Which demand planning tools give real-time visibility into inventory and purchasing?

Look for one view of on hand, committed, on order and in transit stock per SKU and location. Many tools describe this, but sync frequency varies, so ask how often each data source updates in your setup.

Which demand planning platforms auto-build constrained order plans that respect lead times?

Most replenishment apps use lead time to time reorders and some apply MOQs. Joint planning of capacity, materials and lead times is the domain of MRP and enterprise suites. Keep a human approval step either way.

How much does Forthcast cost?

Forthcast is $19.99 a month on one plan with no per-SKU fees and a 14-day trial, billed through Shopify (forthcast.io/pricing, checked 7 November 2026).

If you need a planning system built around your suppliers, tools and exceptions rather than another shelf product, Forthsuite's custom ops service starts with a structured audit and a written opportunity report. That work is quoted; it is not a self-serve plan.