Distribution
ERP
Inventory Management
Inventory Allocation: Hard vs Soft Allocation Rules and How ERP Assigns Stock to Orders
Last updated: October 12, 2026 · Independent guide · We do not sell rankings or coverage.
Inventory allocation is the set of rules your ERP or inventory system uses to tie available stock to specific orders, channels and warehouses, and to decide who gets what when demand exceeds supply. Most systems use two levels: a soft reservation that lowers available stock but can still be moved, and a hard allocation that locks units to one order until it ships. The rule you choose for shortages (first come first served, customer priority or fair share) decides your fill rate by customer and how long backorders sit. Below are the stages and where NetSuite, Business Central, Acumatica, Cin7 and Linnworks keep the settings.
The inventory allocation process at a glance
- Define availability so everyone uses the same formula for on hand, allocated, available and available to promise.
- Soft-reserve stock at order entry so the same units are not promised twice.
- Hard-allocate at release by firming the lines that are about to be picked.
- Apply the shortage rule when open demand is larger than available stock.
- Split stock across channels and warehouses with buffers, caps and location rules.
- Reallocate and release on receipt as cancellations, short picks and inbound stock change the picture.
Order entry, credit and invoicing are covered in our guide to sales order processing in ERP, and partial shipments and customer notices are covered in our guide to backorder management. This page focuses on the allocation decision itself.
Who owns each stage
This RACI-style table reflects a typical distributor or multichannel brand. Your split may differ, but every stage needs one accountable owner.
| Stage | Responsible | Accountable | Consulted / Informed |
|---|---|---|---|
| Define availability | ERP administrator | Inventory manager | C: finance, ecommerce |
| Soft reservation | System, customer service | Customer service lead | I: sales |
| Hard allocation | Planner or warehouse lead | Operations manager | I: warehouse |
| Shortage rule | Inventory manager | Head of operations | C: sales, finance. I: key accounts |
| Channel and warehouse split | Ecommerce or channel manager | Inventory manager | C: warehouse. I: marketing |
| Reallocation and release | Planner | Operations manager | C: purchasing |
Stage 1: Define availability, and how allocation differs from ATP and backorders
Allocation, available to promise and backorders are three different things. Allocation ties existing or inbound stock to a specific demand. Available to promise (ATP) answers when a requested quantity can ship; Business Central describes ATP as an availability check of the “unreserved quantities in inventory” with regard to planned production, purchases, transfers and sales returns (Microsoft Learn, August 21, 2025). A backorder is the open quantity left after allocation could not cover the line.
The link between them is the available figure. Cin7 Core states the formula plainly: available quantity equals on hand minus allocated, where allocated is stock reserved for pending sale and work orders (Cin7 Core Help, no date shown). Linnworks calculates available stock as total stock minus stock reserved for open orders (Linnworks Help, February 23, 2022).
Inputs and output: on-hand balances, open orders and inbound orders become one documented formula for available stock. Controls: decide whether quarantined or in-transit stock counts, and use the same definition in the ERP, the ecommerce sync and reports. What goes wrong: the warehouse reports on hand, ecommerce syncs available and sales quotes ATP, and nobody can explain the gap.
Stage 2: Soft reservation at order entry
A soft reservation reduces available stock when an order is saved or authorized, but the system or a planner can still move those units to a more important order. In Business Central, order tracking is a system-generated link between supply and demand that changes as orders are entered, while a reservation is “a firm link that connects a specific demand and a specific supply” and is ignored by planning (Microsoft Learn, March 17, 2026). A Business Central reservation is therefore the closer match to a hard allocation.
In NetSuite, the commit setting on a sales order (Available Qty, Complete Qty or Do Not Commit) defaults from Accounting Preferences and controls whether and how much stock is committed (Oracle NetSuite Help, no date shown). Committed lines can still be reallocated to another order unless they are firmed (Oracle NetSuite Help, no date shown).
Controls: release reservations when an order is canceled and report old ones. What goes wrong: stale reservations make stock look sold out while it sits on the shelf.
Stage 3: Hard allocation at release
A hard allocation locks units to one order so no rule or user action moves them without a deliberate override. It belongs where reversing it would cost money: after payment, at pick release, or for a contract delivery. TrueCommerce, which sells supply chain software, recommends soft allocation in early stages while orders may change and hard allocation once demand is confirmed or near its due date (TrueCommerce, February 13, 2023).
NetSuite has two native options. Without Supply Allocation, setting Item Commitment Transaction Ordering to Order by Order Priority adds a Firmed box to order lines, and firmed lines “are no longer eligible for reallocation to another order” (Oracle NetSuite Help, no date shown). With Supply Allocation, a strategy uses Reserved Allocation, which NetSuite can reallocate, or Firm Allocation, which only a user can move (Oracle NetSuite Help, no date shown).
Controls: limit who can firm or unfirm lines and log each override. What goes wrong: hard-allocating everything at order entry, so one large early order holds a whole receipt.
Stage 4: Apply the shortage rule
When open demand exceeds available stock, you need one of four common rules:
- First come, first served (FCFS): the oldest order or requested date wins. It is easy to defend but ignores customer value.
- Priority customer: a numeric rank on the customer or order decides the sequence. NetSuite’s Default Order Priority field on the customer record ranks lower numbers first, so priority 1 beats priority 2 (Oracle NetSuite Help, no date shown).
- Fair share or ratio: every order gets the same percentage of its demand. Business Central’s Reservation Worksheet offers Basic (No Conflicts), Equally and By Customer Priority policies, but Equally splits stock evenly rather than by ratio: 12 units against a sales order for 10 and a job for 7 gives each 6 (Microsoft Learn, August 21, 2025). A true pro-rata split usually needs a worksheet or extension.
- Hybrid: protect a floor for priority accounts, then share the rest pro rata.
Worked shortage example
Illustration (constructed numbers, not real data): you have 600 units of one SKU and four open orders totaling 1,000 units. Order dates and priorities are shown in the table.
| Order (date, priority, qty) | FCFS | Priority | Fair share (60%) |
|---|---|---|---|
| Distributor B (Oct 1, priority 3, 300) | 300 | 0 | 180 |
| Retail chain C (Oct 2, priority 2, 200) | 200 | 200 | 120 |
| Key account A (Oct 3, priority 1, 400) | 100 | 400 | 240 |
| Dealer D (Oct 4, priority 4, 100) | 0 | 0 | 60 |
| Orders shipped complete | 2 of 4 | 2 of 4 | 0 of 4 |
Unit fill rate is 60% under every rule; what changes is who waits. FCFS leaves the key account with a quarter of its order. Priority leaves B and D with nothing. Fair share completes no order, which means four backorders and four second shipments. A hybrid that guarantees A 80% (320 units) and splits the other 280 pro rata gives B 140, C 93 and D 47. Choose by asking which costs more: an unhappy key account, or more partial shipments and freight.
Controls: write the rule down, have sales and finance sign it, and configure it. What goes wrong: reps move stock to their own accounts, and the rule changes with every complaint.
Stage 5: Split stock across channels and warehouses
Multichannel brands must also decide how much of the available figure each marketplace or store may sell. Because orders can arrive before the latest stock update reaches every channel, teams usually publish less than the full quantity.
- Cin7 Core pushes available stock from the mapped location, or the sum of several mapped locations, to Shopify, and lets you set an inventory buffer per product or for all products on a sales channel (Cin7 Core Help, no date shown).
- Linnworks caps what a channel sees with Max Listed, set for the whole channel under Settings > Channel Integration > Edit Channel > Inventory > Max listed or per SKU on the mapping screen, where the SKU value takes priority (Linnworks Help, October 7, 2021). Location Mapping decides which locations feed each channel; if all are disabled, Linnworks sends combined stock from every location, except for multi-location channels such as Shopify (Linnworks Help, February 23, 2022).
- Acumatica fills orders from more than one warehouse and can split a sales order into shipments from different warehouses (Acumatica sales order datasheet, March 20, 2025).
Controls: review buffers and caps before promotions and peak season, and document which locations feed which channel. What goes wrong: one channel sells units another channel already sold, which leads to cancellations. For the wider channel picture, see our article on distributor ERP and omnichannel fulfillment.
Stage 6: Reallocate and release on receipt
Allocations go stale as orders are canceled, picks come up short and receipts move. In NetSuite, turning on Perform Item Commitment after Transaction Entry under Setup > Accounting > Preferences > Accounting Preferences makes NetSuite allocate automatically when new quantities become available, in the sequence set by Item Commitment Transaction Ordering: transaction date, expected ship date or order priority (Oracle NetSuite Help, no date shown). Clear it and planners commit manually at Transactions > Inventory > Schedule Commit Orders > Run Now (Oracle NetSuite Help, no date shown).
Acumatica handles mass allocation and deallocation on its Manage Sales Allocations screen, shows customer and order priorities for unallocated orders sorted by date, and lets users override the suggestions (Acumatica sales order datasheet, March 20, 2025).
Controls: run reallocation on a fixed schedule, such as daily after receiving, and log manual moves. What goes wrong: received stock goes to whichever order the picker reaches first. If shortages are chronic rather than occasional, fix supply first; our guide to reducing stockouts without tying up cash covers that side.
Metrics to track
- Fill rate, three ways and by customer tier: units, lines and orders shipped complete on the first shipment, each divided by the total. In the example, unit fill rate was 60% under every rule while order fill rate ran from 0% to 50%.
- Backorder aging: open backordered lines in buckets such as 0 to 7, 8 to 14, 15 to 30 and over 30 days. Growth in the older buckets means allocations or supply are stuck.
- Allocated but not shipped: units allocated longer than your normal order-to-ship time, usually stale reservations.
- Manual override rate: manual reallocations divided by allocated lines. A high rate means the configured rule does not match how the business decides.
- Channel cancellation rate: orders canceled for lack of stock, by channel.
How software supports each stage
| Product | Soft vs hard | Shortage rules | Channel and warehouse |
|---|---|---|---|
| Oracle NetSuite | Committed vs Firmed lines; Reserved vs Firm Allocation with Supply Allocation | Transaction date, expected ship date or customer order priority | Not covered in the pages we reviewed |
| Business Central | Order tracking vs reservation | Basic (No Conflicts), Equally, By Customer Priority | Not covered in the pages we reviewed |
| Acumatica | Allocation rules for each step of the sales process | Customer and order priorities for unallocated orders sorted by date, with manual override | Multi-warehouse fill and split shipments |
| Cin7 Core | Allocated quantity on pending orders | No priority rule in the pages we reviewed | Per-channel buffers; mapped locations |
| Linnworks | Stock reserved for open orders | No priority rule in the pages we reviewed | Max Listed caps; Location Mapping per channel |
NetSuite has the deepest native rule set of the five, but Supply Allocation sits under Advanced Inventory Management in the help, so confirm licensing. Cin7 Core and Linnworks are strongest at keeping channel quantities accurate; in the pages we reviewed neither documents a priority rule for B2B shortages.
How we researched this
We read the pages ranking for “inventory allocation” and “hard vs soft allocation,” from Red Stag Fulfillment, NetSuite, TrueCommerce and Finale Inventory. They define push, pull, hard and soft allocation but give no worked shortage example and name no product settings. We then read vendor documentation for NetSuite, Business Central, Cin7 Core and Linnworks and Acumatica’s sales order datasheet on October 12, 2026. No vendor paid for inclusion.
Related guides
- Negative Inventory in ERP: Causes, Costing and Fixes
- Pick Pack Ship Software: 2026 Buyer’s Guide and Prices
- Stock Transfer Orders: Process, In-Transit and ERP Setup
Frequently asked questions
What is the difference between soft and hard allocation?
Soft allocation reduces available stock but can be moved to another order by the system or a planner. Hard allocation locks units to one order until it ships or someone deliberately overrides it. Most teams soft-reserve at order entry and hard-allocate at payment or pick release.
Is inventory allocation the same as available to promise?
No. Allocation ties stock to a specific order, while ATP calculates when a requested quantity can ship. ATP usually counts only unreserved stock plus planned receipts, so allocations directly change the dates ATP returns.
How should I allocate inventory when I cannot fill every order?
Choose first come first served, customer priority, fair share or a hybrid, and configure it in your system. Unit fill rate is the same under every rule, but who gets a complete order is not.
How do I stop overselling across Shopify, Amazon and my ERP?
Publish less than your full available stock to each channel. Cin7 Core supports per-channel buffers and Linnworks supports Max Listed caps and per-channel location mapping. Review both before peak periods.
Sources
- Oracle NetSuite Help: Setting Inventory Allocation Preferences, no date shown
- Oracle NetSuite Help: Committing Orders, no date shown
- Oracle NetSuite Help: Setting Customer Commitment Priorities, no date shown
- Oracle NetSuite Help: Item Commitment Transaction Ordering Set to Order by Order Priority, no date shown
- Oracle NetSuite Help: Creating Allocation Strategies, no date shown
- Microsoft Learn: Reserve items (Business Central), August 21, 2025
- Microsoft Learn: Design details, reservation, order tracking and action messaging, March 17, 2026
- Microsoft Learn: Calculate order promising dates, August 21, 2025
- Acumatica: Sales Order datasheet, March 20, 2025
- Cin7 Core Help: Calculation of Available, On Hand and Allocated stock quantity, no date shown
- Cin7 Core Help: Stock levels in Shopify, no date shown
- Linnworks Help: Max Listed quantity and its uses, October 7, 2021
- Linnworks Help: Incorrect stock levels (troubleshooting), February 23, 2022
- TrueCommerce: When to use hard and soft allocation, February 13, 2023 (TrueCommerce sells supply chain software)
Sherman Hsieh
Independent analysis of enterprise software — ERP, CRM and more
