The manufacturing store room guide — how to structure RM, WIP, FG, and rejection stores in a WMS

Buy a warehouse management system built for a distribution centre and drop it into a factory store room, and it will fight you at every step. A distribution WMS assumes goods come in, sit still, and go out unchanged. A manufacturing store room does the opposite: material comes in, gets issued to production, changes form, comes back as work-in-progress and then finished goods, and generates rejections and scrap along the way. Modelling that correctly starts with getting the store structure right — this guide covers how.

For the difference between the two disciplines, see inventory vs warehouse management. For the industry product, see Manufacturing WMS.

Why manufacturing is different

The defining feature of a factory store is transformation. The same physical material exists in several states as it moves through production, and each state has different rules about who can draw it, where it lives and how it is valued. A store structure that lumps everything into one “stock” bucket loses the ability to answer basic questions: how much raw material is free to issue, what is committed to open work orders, what has been made but not yet inspected, what failed inspection. You need distinct stores for distinct states.

The store types you need

A typical manufacturing operation needs six store types. In Fast WMS these are modelled as separate stores (warehouses), each with its own bins:

Keeping these apart is what lets the system tell you your free-to-use raw material, distinct from what is already on the floor, distinct from what failed QC — three numbers a single stock bucket collapses into one misleading total.

Movements between stores

Structure is only half the picture; the movements between stores are the other half. The core manufacturing movements Fast WMS records are:

• Receipt to RM — goods received against a purchase order into the raw-material store, with lot and supplier traceability. See GRN & inbound.
• Issue to work order — RM issued to a specific production order, moving it from free stock into WIP.
• Finished-goods receipt — completed output booked into the FG store, ready for inspection and dispatch.
• Rejection / quarantine moves — failed material flagged and segregated so it cannot be issued or shipped.
• Scrap and adjustment — write-offs and reconciliations, each posting a ledger entry so book and physical stay aligned.

Kitting and de-kitting

Manufacturing store rooms also assemble and disassemble. Kitting gathers the components of an assembly — per the bill of materials — into a single issue, so the shop floor receives a complete kit rather than chasing parts. De-kitting does the reverse, breaking an assembly back into components. Fast WMS records both against the BOM structure, so the stock effect of building or breaking a kit is captured correctly rather than fudged with manual adjustments.

Reservation and the two inventory commits

Two concepts keep a factory store honest. First, reservation: material can be reserved against a work order so it is visibly committed and not double-issued, then de-reserved if plans change. Second, the same two-commit discipline that governs the whole platform — inbound stock commits when put-away is confirmed, and outbound stock leaves in two legs (at pick-confirm and at dispatch), while invoicing never moves stock. In a manufacturing context that means your RM is genuinely on-hand only once racked and confirmed, and your FG genuinely leaves only when dispatched — not when an invoice is raised.

Bins within stores

Each store is subdivided into bins, so a large raw-material store is not one undifferentiated space but a grid of addressable locations. Every pallet sits in a specific bin with an append-only history, so “where is this material?” always has a precise answer — the same bin and location management that makes distribution warehouses findable makes factory stores findable too.

Frequently asked questions