AI Demand Forecasting Tools Compared: Inventory Planner, Cogsy, ToolsGroup, Streamline, RELEX, Logility, and Fountain9 — with SKU-Level Forecast Cost Math (2026)

**Inventory Planner** is the workhorse of the Shopify and BigCommerce mid-market. It pulls sales history out of your storefront, ERP, or 3PL, runs an ensemble of statistical and ML forecasts at the SKU-location level, and tells your buyer what to reorder, when, and in what quantity. The forecasting math isn't exotic — it's seasonal decomposition, exponential smoothing, and gradient boosting layered together — but the Shopify-native UX is the moat. Plans start at $249/mo (Essential), step up to $749/mo (Advanced), and top published tier is $1,499/mo (Premium) per https://www.inventoryplanner.com/pricing/. For most 7- and 8-figure brands, it is the default answer.

**Cogsy** is what Inventory Planner would look like if it were built in 2022 for cash-conscious DTC operators. The product fuses demand forecasts with cash-flow modeling, marketing-lift signals from Klaviyo, and a Slack-first surface that nudges founders rather than buyers. Plans run $299/mo (Foundation), $549/mo (Growth), and $999/mo (Advanced) per https://cogsy.com/pricing. If your CFO and your head of ops fight about whether to reorder, Cogsy is built for that fight.

**ToolsGroup SO99+** is the grown-up. It pioneered probabilistic demand forecasting in supply-chain software and still wins enterprise deals on slow-moving SKUs and long-tail intermittent demand — the exact problem that breaks Shopify-tier tools. Pricing is quote-only; published market benchmarks put SO99+ deployments in the ~$50K–$300K/yr range depending on SKU count, locations, and number of seats. See https://www.toolsgroup.com/ for solution scope.

**Streamline** (GMDH Streamline) is the dark horse. It sells a desktop-and-cloud hybrid that scales from a single user at $250/mo (Solo) to $599/mo (Pro) to Enterprise from $2,000/mo, with on-prem deployment for security-sensitive buyers per https://gmdhsoftware.com/pricing-streamline. The GMDH neural-network forecasting heritage is real, not marketing — and it's one of the few tools at this price point that will run inside your firewall.

**RELEX Solutions**, **Logility**, and **Fountain9** round out the enterprise tier. RELEX is the unified retail planning suite favored by grocery and CPG chains, with deployments typically in the $150K–$1M+/yr range (https://www.relexsolutions.com/). Logility is the supply-chain planning incumbent at $100K–$500K/yr (https://www.logility.com/). Fountain9 Kronoscope is the AI-first newcomer at $25K–$100K/yr (https://www.fountain9.com/) — same enterprise capabilities, lower price, less established footprint. All three sell via quote, demo, and pilot.

**Inventory Planner** integrates natively with Shopify, Shopify Plus, BigCommerce, Amazon Seller Central, NetSuite, QuickBooks, and Xero. It expects clean SKU and location data and falls over if your storefront has duplicate variants or your 3PL emits inconsistent SKUs. Implementation for a mid-market brand is 2–4 weeks if your data is clean, 8–12 if it isn't. The architecture is a hosted SaaS with daily sync — not real-time — which is fine for replenishment but useless for promotional surge planning.

**Cogsy** is Shopify-native by design, with first-class integrations into ShipBob, Klaviyo, and Slack. The model retrains nightly on your sales + marketing calendar, and the unique angle is that Klaviyo campaigns and ad spend get treated as features the forecast learns from. If you don't use Shopify, don't bother — Cogsy isn't built for you. See product scope at https://cogsy.com/pricing.

**ToolsGroup SO99+** plugs into SAP, Oracle, Microsoft Dynamics, JDA, and almost any ERP via custom connectors. Deployments are private cloud or on-prem and run 3–9 months. The probabilistic forecasting engine outputs full demand distributions, not single point estimates — meaning you can set service levels at the SKU level and let the math tell you what stock to hold. That capability is genuinely hard to replicate in a $749/mo Shopify app.

**Streamline** stands out for offering both a desktop client and a cloud SaaS, with the desktop running inside your firewall against an Excel, SQL Server, SAP, or NetSuite source. For mid-market manufacturers and distributors with regulated data, that on-prem option is the entire reason they buy. See https://gmdhsoftware.com/pricing-streamline for deployment options and pricing tiers.

**RELEX Solutions** and **Logility** are full unified planning suites — demand, supply, S&OP, replenishment, allocation, store-level forecasting — sitting on top of a data lake architecture. RELEX is famously good at grocery and fresh-food forecasting (shelf life is a first-class concept). Logility leans into demand sensing, where short-cycle signals adjust forecasts daily. **Fountain9** is API-first and SaaS-only, with REST endpoints and pre-built connectors for SAP, NetSuite, and Shopify Plus — making it the easiest enterprise option to integrate, per https://www.fountain9.com/.

**Inventory Planner's** $249/mo Essential covers up to ~3,000 SKUs and one storefront — fine for a single-channel Shopify brand under $5M revenue. Advanced at $749/mo unlocks multi-warehouse, advanced replenishment logic, and additional integrations; Premium at $1,499/mo adds SSO, dedicated support, and large SKU counts. All three tiers per https://www.inventoryplanner.com/pricing/. The honest take: if you're below $3M revenue, Essential is enough; the jump to Advanced should happen when you have a second warehouse or hit ~10K SKUs.

**Cogsy's** $299/mo Foundation gives you forecasting and PO generation. Growth at $549/mo adds the cash-flow planner and marketing-lift features that are the actual reason to buy Cogsy. Advanced at $999/mo unlocks SSO, multi-brand, and white-glove onboarding (https://cogsy.com/pricing). Skip Foundation — Growth is where the differentiation lives.

**Streamline's** $250/mo Solo is a single-user desktop license; Pro at $599/mo adds multi-user and cloud sync; Enterprise from $2,000/mo unlocks on-prem deployment, SAP integration, and SSO per https://gmdhsoftware.com/pricing-streamline. The real number for an enterprise rollout with 5–10 seats and on-prem is closer to $30K–$60K/yr — still a fraction of ToolsGroup or RELEX.

**ToolsGroup** publishes no pricing, but field deals are widely reported in the $50K–$300K/yr range, gated by SKU count, sites, and number of planners. A mid-market manufacturer with ~50K SKUs and 3 DCs should expect ~$75K–$120K/yr. **Fountain9 Kronoscope** at $25K–$100K/yr is the most accessible enterprise option and worth quoting against ToolsGroup if you want a probabilistic engine on a startup budget.

**RELEX Solutions** and **Logility** are the heaviest commitments. RELEX retail deployments run $150K–$1M+/yr depending on store count, category, and modules (replenishment, allocation, S&OP). Logility runs $100K–$500K/yr. Both lock you into 3-year minimum terms in practice, even when paper says otherwise. Pricing is as of June 2026 — verify at vendor.com/pricing before signing anything.

Every demand forecast has a cost-per-SKU-per-month figure buried inside it, and once you compute that number the vendor lineup re-sorts itself. The formula is simple: monthly forecast cost ÷ (active SKUs × locations) = cost per SKU-location per month. For a brand with 5,000 SKUs in a single warehouse on **Inventory Planner** Advanced at $749/mo, that's $749 ÷ 5,000 = $0.15 per SKU per month, or $1.80 per SKU per year. That is the floor for self-serve SaaS in 2026.

Run the same math on **Cogsy** Growth at $549/mo for a 2,000-SKU DTC brand: $549 ÷ 2,000 = $0.27 per SKU per month. Higher per SKU than Inventory Planner because Cogsy targets brands with narrower SKU counts and richer marketing data per SKU — you're paying for the cash-flow and Klaviyo layer, not just the forecast. Pricing per https://cogsy.com/pricing.

**Streamline** at the Pro tier ($599/mo) for 10,000 SKUs across 3 locations = $599 ÷ 30,000 SKU-locations = $0.02 per SKU-location per month. That is dramatically cheaper than the Shopify-native tools because Streamline is built to scale at SKU count and lives outside the Shopify mark-up zone. Verify at https://gmdhsoftware.com/pricing-streamline.

**ToolsGroup SO99+** at a midpoint deal of $150K/yr for 50,000 SKUs across 5 DCs = $12,500/mo ÷ 250,000 SKU-locations = $0.05 per SKU-location per month. Cheaper per SKU than Cogsy at scale, but the all-in figure is 25× the price. **Fountain9** at $60K/yr for the same footprint comes out to ~$0.02 per SKU-location — competitive with Streamline, with a probabilistic engine attached.

**RELEX** at $400K/yr for a 200-store grocery chain with 30,000 SKUs per store = $33K/mo ÷ 6M SKU-locations = $0.005 per SKU-location per month. The per-unit math looks brilliant — but you must justify $400K of total spend, not $0.005 per row. The lesson: SaaS-tier tools win the per-SKU race below ~$50K/yr of total spend; enterprise tools win the per-SKU race once you cross ~100K SKU-locations and need the planning depth.

Shopify or BigCommerce brand, $1M–$30M revenue, 500–10K SKUs, single warehouse: **Inventory Planner** Essential or Advanced wins almost every time. The integration is plug-and-play, the replenishment logic is mature, and the price per SKU stays sane. If your buying team lives in Shopify Admin, this is the answer.

DTC brand on Shopify, $3M–$20M revenue, narrow SKU count (50–500 SKUs), heavy promotional cadence, founder-led ops: **Cogsy** Growth at $549/mo wins per https://cogsy.com/pricing. The Klaviyo + Slack + cash-flow surface beats Inventory Planner here, even though Inventory Planner has the better forecast engine. You're buying decision support, not forecasts.

Mid-market manufacturer or distributor, 10K–100K SKUs, 2–10 warehouses, NetSuite or SAP backend, regulated data: **Streamline** Pro or Enterprise wins on price and the on-prem option, but **ToolsGroup SO99+** wins if you have meaningful slow-moving or intermittent demand (parts, spares, long-tail SKUs). Quote both. Streamline pricing at https://gmdhsoftware.com/pricing-streamline; ToolsGroup quoted via https://www.toolsgroup.com/.

Retail chain or CPG with 50+ stores, fresh or perishable categories, multi-echelon replenishment: **RELEX Solutions** wins. The grocery domain expertise is unmatched and competitors lose on shelf-life modeling. Budget $150K–$1M+/yr and a 6–12 month implementation per https://www.relexsolutions.com/.

Large supply-chain org needing classic S&OP, demand sensing, and integrated planning across an existing SAP or Oracle stack: **Logility** is the safe incumbent at $100K–$500K/yr. AI-first challenger budget under $100K/yr with enterprise capabilities: **Fountain9 Kronoscope** at $25K–$100K/yr per https://www.fountain9.com/. Run a 90-day pilot before signing the multi-year.

Forecasting tools touch your most sensitive operational data — sales by SKU, margins, supplier lead times, and customer-level demand patterns. **Inventory Planner** and **Cogsy** are SaaS-only with SOC 2 Type II and standard SSO on top tiers. They store data in AWS us-east-1 by default with no published data-residency options below Premium and Advanced respectively. If you're an EU brand under GDPR with no DPA flexibility, ask before signing.

**Streamline** is the rare tool that ships an on-prem desktop and on-prem server option per https://gmdhsoftware.com/pricing-streamline. For pharma, defense, or anyone who can't push SKU-level sales data to a third-party cloud, this is the differentiator. **ToolsGroup**, **RELEX Solutions**, and **Logility** all support private-cloud and on-prem deployment for enterprise contracts; **Fountain9** is SaaS-only with regional data-residency options.

On evaluation rigor: never sign a multi-year on a demo. Demand a 60–90 day paid pilot with your actual SKUs and your actual sales history, measured against a control of either your current process or a naive baseline (last year + seasonality). The metric that matters is forecast accuracy at the SKU-location-week level, MAPE or WAPE — not aggregate forecast accuracy at the brand level, which every vendor wins.

The biggest procurement gotcha is SKU-count creep. Mid-market tools price by SKU bands; enterprise tools price by total complexity. If you launched 5,000 new SKUs in a Black Friday push and didn't tell your account manager, expect a renewal repricing. Build the SKU-count clause into the original contract — fixed pricing for ±25% SKU variance is achievable on **Inventory Planner**, **Cogsy**, and **Streamline** with a little negotiation.

Lastly: AI-feature claims are mostly marketing in 2026. Every vendor here has shipped some form of ML for years. What actually matters is whether the platform can explain a forecast to your buyer — which inputs drove it, what the confidence interval is, and what overrides are recorded. **ToolsGroup** and **RELEX** lead on explainability; **Cogsy** and **Inventory Planner** lead on simplicity. Pick your trade-off honestly.

If your security team has a firm 'no third-party cloud for operational data' rule, your shortlist collapses to **Streamline**, **ToolsGroup**, **RELEX Solutions**, and **Logility**. Of those, **Streamline** is the cheapest by an order of magnitude — Enterprise from $2,000/mo per https://gmdhsoftware.com/pricing-streamline, with a real on-prem desktop and server stack that runs inside your firewall against your existing SQL Server or SAP.

**ToolsGroup SO99+** offers both private-cloud (hosted in your AWS, Azure, or GCP account) and on-prem deployment, but expect total cost in the $100K–$300K/yr range once you add implementation, support, and the planner seats. The probabilistic forecasting engine is the reason to pay that — not the deployment model. Reference at https://www.toolsgroup.com/.

**RELEX Solutions** and **Logility** both deploy in private cloud and on-prem for enterprise contracts. RELEX especially is built for retailers that already run their own data center footprint. Budget $300K+/yr and a 9–12 month implementation. These are not shortcut purchases.

**Fountain9 Kronoscope** is SaaS-only as of June 2026, but it does offer regional data residency in the US, EU, and APAC under enterprise contracts per https://www.fountain9.com/. If your residency requirement is geographic (GDPR or APPI) rather than firewall-strict, Fountain9 is viable at a fraction of the RELEX price.

The 2026 reality is that on-prem demand forecasting is a shrinking niche. Even regulated industries are moving to private-cloud deployments under their own KMS keys. If you're early in this decision and your security team is open to private cloud, you'll save 30–50% versus full on-prem and get faster model retraining. Push back on 'must be on-prem' if it's a legacy reflex rather than a real compliance requirement.

**Inventory Planner** fails on long-tail intermittent demand. The ensemble it runs is great for high-velocity SKUs and predictable seasonality, but the math breaks down on parts and spares with months of zero sales between orders. If 40%+ of your SKUs are slow-movers, you'll be manually overriding constantly and eventually replacing it with ToolsGroup or Streamline.

**Cogsy** fails outside Shopify. If your stack is BigCommerce, WooCommerce, Magento, or anything custom, Cogsy isn't your tool. It also fails for brands with >5,000 SKUs — the UX wasn't built for that scale, and the per-SKU pricing math gets ugly fast. Verify limits at https://cogsy.com/pricing before you start a trial.

**Streamline** fails on UX. The desktop client is genuinely powerful but feels like 2015 software. Planners coming from Inventory Planner or Cogsy will hate the first week. If you don't have a dedicated demand planner, Streamline is the wrong choice regardless of price.

**ToolsGroup** fails on implementation timeline. Six to nine months is standard, and the consulting cost frequently equals the first-year license. If you need forecasting live in 60 days, ToolsGroup is the wrong shape — go Streamline, Fountain9, or Inventory Planner depending on your scale.

**RELEX Solutions** and **Logility** fail on flexibility. Both are exceptionally good at the patterns they were built for (RELEX for retail, Logility for classic S&OP) and notably worse at adjacent patterns. **Fountain9** fails on track record — the platform is technically strong, but you'll be one of fewer than 500 customers and the partner ecosystem is thin. Take a calculated bet, not a blind one.