Use Inventory Items in Projects in Business Central
- Alfredo Iorio
- 22 hours ago
- 12 min read
In Dynamics 365 Business Central, Projects and Inventory are built as two distinct but interconnected ledgers. This separation is intentional and reflects the different responsibilities each module carries.
Inventory must always maintain precise physical quantities and cost layers for every item, regardless of how the item is sold, purchased, consumed as a component in a production order or used in a project. When an inventory item is consumed on a project, the system first records an item ledger entry that reduces on-hand stock and captures the cost according to the item’s costing method.
More about costing method here: Inventory Costing Methods in Business Central: Which One to Choose.
The Projects module, on the other hand, needs its own independent view of that same consumption. It tracks the material against the specific project budget, calculates work-in-progress values, and supports profitability analysis and customer billing. Because these two perspectives serve different purposes, one focused on physical inventory accuracy and valuation, the other on contract-level financial control, the system does not merge them automatically. Instead, it provides configurable bridges so finance teams can decide exactly how and when the cost value moves from inventory into the project’s financial picture.
Apply Usage Link: A link between Projects and Inventory
The Apply Usage Link setting creates the first of those bridges. When it is turned on either as a default on the Project Setup page or on an individual project card, the system treats each planned inventory line on the project planning lines as the single source of truth for expected material quantities.
Every time consumption is posted, whether through a project journal, an inventory pick generated directly from the job, or a linked purchase receipt, the remaining quantity on the planning line updates automatically. This persistent link enables several downstream controls that would otherwise be unavailable: automatic reservations against the planned line, item tracking across the full project lifecycle, and seamless synchronisation with assembly-to-order orders.
Without the link, the inventory quantity still decreases correctly through the item ledger entry, and the cost still moves forward. Still, the project planning lines lose their real-time connection to actual usage. The result is that finance teams must perform manual reconciliation at month-end, and features such as direct inventory picks from the job card become unavailable. The setting, therefore, exists to keep the planning lines accurate and actionable, reducing the risk of overstated remaining budgets or untracked material commitments.
Project Posting Groups: how BC connects items and project costs
Project Posting Groups provide the second bridge. These groups define the general ledger accounts that receive the cost value once it leaves the inventory ledger.
Because the Projects module calculates work-in-progress differently from standard inventory costing, it requires its own set of accounts:
The Item Costs Applied Account clears the value out of the inventory valuation.
The WIP Costs Account holds the material cost on the balance sheet while the project is ongoing (depending on the job’s chosen WIP method).
The Recognised Costs Account receives the cost on the income statement once the project’s revenue-recognition rules allow it.
By mapping these accounts once in the posting group and then assigning the group to the project card, the system ensures that the cost value pulled from the item ledger entry lands exactly where your accounting policy requires it.
The WIP method is selected on the job, then controls the timing of any reclassification between WIP and recognised costs. This design gives finance teams full control over classification and timing without forcing every item movement through the same rigid path or duplicating master data.
Taken together, the two ledgers: Item Ledger Entries and Project Ledger Entries, the Apply Usage Link, and the Project Posting Groups ensure that material costs follow the exact financial journey required by your accounting policies.
Inventory remains accurate for physical stock and valuation purposes, while the project ledger remains accurate for budgeting, WIP, and profitability. This architecture prevents common disconnects: materials that disappear from stock but never appear in project cost reports, or costs that hit the wrong profit-and-loss line simply because the job was not mapped to the company’s revenue-recognition policy.
It is the reason the Budget Cost, Actual Cost and Billable Price fields on the project card can be trusted, and why project profitability reports align with inventory valuation reports without constant manual adjustments.
The Role of Line Type in Project Planning Lines
In Dynamics 365 Business Central, the Line Type field on project planning lines serves as the control mechanism that separates internal cost and usage tracking from external revenue recognition within the same record.
This field exists because the Projects module must support different project contract structures, such as time-and-materials engagements, where every material cost is recoverable and fixed-price contracts where billing follows a separate schedule, while maintaining a single planning line table that feeds both the job ledger entries and the sales invoicing process.
For inventory items specifically, the line type determines how the item ledger entry generated by consumption interacts with the project ledger, influencing the flow of cost value into work-in-progress or recognised costs and the corresponding price value into customer invoices.
Budget Line Type
The Budget line type establishes the planned consumption of inventory items strictly for internal project costing and scheduling purposes. When an inventory item line carries this type, the quantity and cost values contribute directly to the job budget calculations and feed into job ledger entries upon posting of usage.
This creates the necessary bridge from inventory, where the item ledger entry reduces on-hand quantity and applies the item’s costing method to the project, where the cost value is routed through into either the WIP Costs Account or the Recognised Costs Account, depending on the job’s WIP method.
Because no price component is recognised for invoicing, this line type keeps the material cost isolated within the project’s internal financial view. The result is that inventory consumption updates project profitability reports and remaining budget fields without generating any sales invoice lines, preserving the distinction between committed material costs and billable revenue.
Billable Line Type
The Billable line type reverses the focus by establishing the planned price for inventory items exclusively for revenue recognition and customer invoicing. In this configuration, the line does not drive cost tracking or usage linkage in the same way as Budget lines; instead, it supplies the selling price and quantity that flow into sales invoice creation.
For inventory items, this means the line type decouples the material from the job ledger’s cost accumulation process. Consumption of the item still generates an item ledger entry, but the associated cost value does not automatically create a corresponding job ledger entry tied to this planning line unless additional configuration bridges it through a separate Budget line.
This design supports fixed-price or milestone-based projects where the invoice amount for materials is predetermined and independent of actual usage costs, allowing the system to maintain a clean separation between inventory valuation adjustments and the revenue side of the project ledger.
Both Budget and Billable Line Type
The Budget and Billable line type creates a unified record that simultaneously handles internal cost tracking and external invoicing for the same inventory item. The quantity and cost values drive job ledger entries and WIP calculations exactly as in a Budget line, while the price values are made available for direct transfer to sales invoices.
This dual role establishes the tightest bridge between the inventory, projects, and the sales posting engines: when usage is posted against an inventory item on a this type of line, the item ledger entry reduces stock, the cost flows through the project posting group into WIP or recognised costs, and the price component remains linked for invoicing without requiring a second planning line.
The configuration dependency with the Apply Usage Link setting on the project must be active for automatic quantity updates to propagate correctly across both cost and price elements of the inventory transaction. This line type, therefore, exists to support hybrid project models where material costs must be fully traceable for profitability analysis while the same quantities are recovered directly from the customer.
Line Type on Source Documents vs. Planning Lines
In Dynamics 365 Business Central, the Line Type field operates differently depending on whether it appears on a project planning line or on the source documents that feed the project: job journal lines and purchase lines. This distinction is built into the architecture to give finance control over when and how planning records are generated versus when actual postings occur.
When Line Type Is Left Unspecified on Journal or Purchase Lines
If the Line Type field is left blank on a job journal line or on a purchase line that references a job task, the system posts the transaction normally: it generates the item ledger entry and creates the corresponding job ledger entry. However, no project planning line is created or updated.
This is the deliberate design of the bridge between the inventory and projects posting engines. The planning lines exist as the controlled, forward-looking view of budgeted and billable quantities. Without a Line Type value on the source document, the system does not establish or maintain the link that would allow posted consumption to update remaining quantities, support automatic reservations, enable item tracking on the planning line, or feed variance analysis against the original plan.
Financial and Operational Implications
The result is that inventory movements are recorded in the item ledger and basic job ledger entries are created, but the project’s planning view remains unchanged.
Remaining budget fields, outstanding commitments on the job card, and any reports that rely on planning lines do not reflect the posted activity. This breaks the real-time synchronisation that the Apply Usage Link setting is intended to support.
The design prevents accidental creation of planning lines from ad-hoc or corrective postings while still allowing the core cost and quantity movements to reach the general ledger through the project posting group. It ensures that only intentional, typed entries contribute to the structured planning layer used for WIP calculations, profitability reporting, and customer invoicing.
The Purchase-to-Project Bridge in Business Central
In Dynamics 365 Business Central, purchasing inventory items for projects establishes a controlled bridge between purchases, inventory and projects. This bridge is necessary because material costs must be captured accurately in inventory valuation while simultaneously feeding project costing, work-in-progress calculations, and profitability analysis. The system supports two primary paths for this integration, both of which maintain the separation between physical stock movements and project financial tracking.
Planning-Driven Purchasing
When inventory items are first planned on project planning lines with a Line Type of Budget or Budget and Billable, the planning lines serve as the demand signal for the planning engine. A user can generate purchase orders using Capable to Promise directly from these planning lines or the planning worksheet. This approach links the planned quantity to the purchase order document via reservations, creating visibility of outstanding purchase orders on the project card.
The link ensures that when the purchase order is posted, the resulting item ledger entry can be traced back to the project via order tracking, but it does not maintain synchronisation between planned and actual material quantities for cost calculation.
Direct Purchasing for a Project
Inventory items can also be purchased by entering a purchase order or purchase invoice line with a direct reference to a Project No. and Project Task No. Or, by using a dedicated action on the project planning line.
When the purchase order line references a project planning line, posting the receipt does three things simultaneously:
It creates a positive item ledger entry for the receipt, increasing physical quantity and updating the item cost according to the item’s costing method.
It immediately creates a negative adjustment item ledger entry that writes the same quantity off to the project.
It creates the Project Ledger Entry of type usage that would otherwise be created by a Project Journal.
Net effect on on-hand inventory: zero change. The item is received and consumed in one posting step and does not remain in general stock. On the Jobs side, this receipt also creates a project ledger entry of type usage. The cost value is routed through the project posting group into either the WIP Costs Account or the Recognised Costs Account, depending on the job’s WIP method. This immediate consumption keeps the planning line’s Remaining Quantity synchronised (when Apply Usage Link is active) and reflects the material commitment accurately on the project card.
Invoice Posting When Linked to a Project Planning Line
Posting the purchase invoice completes the financial side of the transaction, finalising the cost recognition in the project ledger and the general ledger. Any interim accounts or price differences are cleared at this stage, ensuring the full cost value is available for project profitability calculations and the Post Inventory Cost to G/L batch job.
Direct Purchases without a Planning Line
If the purchase order line references a project number and task number but has no linked planning line (or the Line Type is left blank), the receipt still creates the positive item ledger entry. However, the immediate consumption is not generated automatically. The item enters on-hand inventory normally. Consumption of the project must then be recorded separately, either through a project journal line or an inventory pick generated from the job. The job ledger entry of type usage is created only when that separate consumption is posted.
Why the System Does Not Use a Sales Shipment Document
The Sales Shipment document exists only for sales documents, where an item is delivered to a customer as the primary transaction, and the shipment creates the item ledger entries that drive customer invoicing. In the projects module, the item is not sold as a separate deliverable; it is consumed as part of the project work itself. The sales invoice is generated directly from the planning lines or job task using the price component of the Budget/Billable lines, not from a shipment document.
Introducing a sales shipment would create an unnecessary bridge to the Sales ledger and duplicate the consumption posting already handled in the project ledger. The architecture, therefore, routes project item movements exclusively through item ledger entries and project ledger entries, keeping the two subsystems synchronised without involving sales shipment tables or processes.
Assemble to Project Capability
In Dynamics 365 Business Central, Assemble to Project extends the bridge between the Assembly Management and Projects. This capability exists to support projects that require assembled items without maintaining those finished goods in stock ahead of need. It treats the assembled item as project-specific demand, ensuring components are consumed, and the finished item is output and immediately used on the project in a controlled flow.
Automatic Creation of the Assembly Order
When an item with an assembly bill of materials is entered on a project planning line of type Budget or Budget and Billable, and the item’s Assembly Policy is set to Assemble-to-Order, the system automatically creates a linked assembly order. The assembly order quantity matches the project planning line quantity. Its component lines are generated from the item’s assembly BOM, with quantities scaled by the planning line quantity.
The assembly order is reserved exclusively against the project planning line. This reservation establishes a persistent link that synchronises item tracking, availability, and quantity updates between the assembly order and the planning line.
Posting Flow: Assembly and Immediate Consumption
Posting consumption on the project planning line via project journal or inventory pick triggers the assembly order posting automatically. The flow proceeds as follows:
The assembly order consumes the required components through negative item ledger entries, reducing component inventory according to each component’s costing method.
It posts the output of the assembled item as a positive item ledger entry, increasing the assembled item’s quantity and updating the costs.
A negative adjustment item ledger entry immediately writes the assembled item off to the project, resulting in a net zero change to on-hand inventory for the finished item.
Simultaneously, the project module creates a project ledger entry of type usage for the assembled item. The cost value is now calculated from the assembled item’s BOM through the project posting group into either the WIP Costs Account or the Recognised Costs Account, depending on the job’s WIP method.
Accounting Principles: Expense and Billing of Inventory Items on Project Planning Lines
In Dynamics 365 Business Central, the projects module maintains a deliberate architectural separation between the cost and the billing flow for inventory items on project planning lines. This separation exists because project financial reporting must simultaneously track actual incurred material costs for accurate work-in-progress valuation and profitability analysis, while customer invoicing follows the independent commercial terms of the contract.
Cost Flow and Expense Recognition
Consumption of an inventory item, whether automatic at purchase receipt or through a project journal line, inventory pick, or warehouse pick, first creates an item ledger entry. This entry reduces physical quantity and applies the item’s costing method. The cost value then transfers to the projects module through a project ledger entry of type Usage. The Project Posting Group assigned to the job determines the exact general ledger routing:
The Item Costs Applied Account acts as the clearing/contra account that removes the value from inventory valuation.
The WIP Costs Account (balance-sheet capital asset account) receives the cost while the project is open.
The Recognised Costs Account (income-statement expense account) receives the cost once it is recognised.
The timing of the reclassification from WIP to recognised costs is controlled by the WIP Method selected on the project card: Cost Value, Cost of Sales, Percentage of Completion, or Completed Contract. The Post Inventory Cost to G/L batch job then creates the final general ledger entries, ensuring the cost is reflected correctly on the balance sheet and income statement.
More about inventory costing methods in this other post: Inventory Costing Methods in Business Central: Which One to Choose
Billing and Revenue Recognition
Billing operates independently on the price component of the planning line. Only lines with Line Type set to Billable or Budget and Billable contribute price values to sales invoice creation. The price amount, taken from the item card Sales Project Prices List, or entered manually on the planning line, flows directly into the sales invoice when the job task or planning line is invoiced.
No link is required between the posted cost value and the billed price; the two sides remain separate until the invoice is created and posted.
Next Steps
In this post, we have covered the full architectural design that connects the Inventory, Assembly, and Projects in Dynamics 365 Business Central.
These are the key takeaways:
Inventory items always generate item ledger entries first to maintain physical quantity accuracy and apply the item’s costing method. The Projects module receives these costs through project ledger entries of type Usage, with the exact general ledger routing determined by the Project Posting Group and the job’s WIP calculation method.
The Apply Usage Link and Line Type fields (Budget, Billable, or Both) create the controlled bridges that synchronise planning lines with actual consumption while keeping cost flows independent of billing (price) flows. Purchasing, receiving/consumption, and Assemble-to-Project all follow the same pattern: immediate or explicit consumption to the project, net-zero impact on general stock, and cost routing into WIP or recognised costs.
This design guarantees that material costs appear correctly on the balance sheet (WIP) and income statement (recognised costs), while project profitability reports and customer invoices remain accurate and traceable.
If you want to learn more about how to use items for projects, check our training resources for Microsoft Dynamics 365 Business Central here: Dynamics 365 Adoption Training