Types of Inventory: 4 Categories, With Examples by Trade

Taped cartons of stock on metal shelving in a store room, with a ladder behind

The types of inventory are raw materials, work in progress, finished goods and the supplies used up in making them, often called MRO. A business that buys goods to resell unchanged holds a fifth type: goods for resale, or merchandise. Which types you hold depends on whether you make, resell or serve.

The IFRS Foundation groups a maker's inventories a little differently: raw materials, consumable stores, work in process and finished goods. This guide sorts everyday goods from six trades into types, then values one Kigali workshop's stock type by type, in Rwandan francs.

What are the 4 types of inventory?

The four types follow goods through production: materials in, work on the floor, products out, and the supplies that keep it running. The table gives each with examples.

The four types of inventory
TypeWhat it isExamples
Raw materialsMaterials bought to make products, not yet usedCotton for clothing, steel for machinery, timber for furniture
Work in progress (WIP)Products started but not finishedA car on an assembly line, bread dough before baking, a jacket still being stitched
Finished goodsProducts made and ready to sellA boxed laptop, bottled juice, medical kits packed for a hospital
MRO: maintenance, repair and operationsSupplies that keep production running but don't become the productSpare machine parts, lubricant, gloves and safety gear

One business's finished good is another's raw material. Flour is a mill's finished product and a bakery's raw material. The type depends on what you do with the goods, not on the goods.

The fifth type: goods for resale

Most shops, wholesalers and pharmacies make nothing: they buy goods and sell them unchanged. That stock is goods for resale, also called merchandise inventory, and the four-type list leaves it out.

IFRS puts it with finished goods, as assets "held for sale in the ordinary course of business". A supermarket's inventory is almost all of this type.

What IFRS counts as inventory, and where MRO goes

IFRS has no MRO category. Paragraph 13.1 of IFRS for SMEs counts three things as inventory: goods held for sale, goods being made for sale, and a third group. That group is "materials or supplies to be consumed in the production process or in the rendering of services".

The IFRS Foundation's module on inventories then names a maker's four groups: finished goods, work in process, consumable stores and raw materials. Consumable stores are the part of MRO that counts as inventory.

Where MRO items belong under IFRS for SMEs
MRO itemWhere it belongsThe basis
Lubricant used by the machinesInventory: consumable storesExample 4: "The lubricants are inventory"
Cheap tools worn out within a yearInventory: consumable storesInventory if not used in more than one period
Spare parts for machinesUsually inventory"Spare parts are usually classified as inventory"
Major spare parts used over several periodsEquipment, not inventoryThey are property, plant and equipment
Cleaning products and stationery for the officeSupplies: an expenseParagraph 13.1: not used in production or in a service you sell

So the popular list mixes two things. Count consumable stores and most spare parts as inventory, and expense what runs the office. Inventory vs supplies gives the test, and MRO inventory covers managing it.

Types of inventory by trade

The same columns look different in every trade. The table sorts typical goods for six kinds of business.

Which types of inventory six businesses hold
BusinessRaw materialsWork in progressFinished goods or goods for resaleConsumable stores
BakeryFlour, sugar, yeast, bread bagsDough proving, loaves in the ovenBread and cakes; soft drinks bought to resellOven spares, baking paper
TailorFabric, thread, buttons, zipsCut pieces, half-sewn uniformsFinished uniforms; school socks bought to resellMachine needles and oil
Furniture workshopTimber, foam, glue, varnishFrames assembled but not finishedChairs and beds; mattresses bought to resellSaw blades, sanding belts
Juice makerFruit, sugar, bottles, labelsJuice in the tanksCartons of juiceLubricant for the filling machine
PharmacyNoneNoneMedicines and cosmetics, all for resaleNone
Hardware shopNoneNoneCement, paint and tools, all for resaleNone

A pharmacy or a hardware shop holds one type and manages it one way. A workshop holds all of them, and each is bought, counted and valued in its own way, as the next example shows.

For example: one workshop's inventory, type by type

For example, a furniture workshop in Kigali lists its stock at the end of June. The figures are illustrative, not a real workshop's.

For example: a Kigali workshop's inventory at the end of June (RWF)
GoodsTypeHow its cost is builtRWF
Timber in the storeRaw materialsPurchase price and transport2,400,000
Glue, screws and varnishRaw materials, indirectPurchase price180,000
12 chairs assembled, not yet finishedWork in progressMaterials 360,000 + labour and overheads 120,000480,000
20 finished chairsFinished goods20 × (materials 45,000 + labour and overheads 20,000)1,300,000
10 mattresses bought to sell with bedsGoods for resale10 × 85,000 purchase cost850,000
Spare saw blades and sanding beltsConsumable storesPurchase price90,000
Total inventory5,300,000
Cleaning products and office paperSuppliesExpensed when boughtNot inventory
The table sawEquipmentDepreciated over its working lifeNot inventory

Raw materials hold nearly half the money, RWF 2,580,000 of RWF 5,300,000. That is where the workshop's buying discipline pays most.

Work in progress and finished goods carry labour and overheads as well as materials, under paragraphs 13.5 and 13.8 of IFRS for SMEs. Valued at materials only, the chairs would show RWF 520,000 less, understating the workshop's inventory by almost a tenth.

Types of inventory by purpose

A second way to sort stock is by why you hold it, and it cuts across the first. A carton of cooking oil can be goods for resale by type and safety stock by purpose.

Inventory sorted by purpose
PurposeWhat it is
Cycle stockWhat you sell between one delivery and the next; its size is your reorder quantity
Safety stockThe buffer for late deliveries and busy days, set as in how to avoid overstocking and stockouts
Anticipation stockBought ahead of a season or an expected price rise
In-transit stockBought and on its way, not yet on your shelf: see in-transit inventory
Decoupling stockA buffer between two production steps, so a stop at one doesn't stop the other
Consignment stockA supplier's goods on your shelf, paid for once sold: see consignment inventory
Dead stockStock that hasn't sold for months: see dead stock

Why the type of inventory matters

The type decides how you value goods, how you reorder them and how often you count them. Treating a workshop's timber like a shop's soap leads to the wrong order at the wrong time.

How each type is valued, reordered and counted
TypeValued atReordered fromCounted
Raw materialsLanded purchase costProduction use and the supplier's lead timeCostly materials weekly
Work in progressMaterials, labour and overheads so farNot reordered: it is finishedAt each period end
Finished goodsFull production costWhat sells, and how long a batch takesWith your regular counts
Goods for resaleLanded purchase costSales and the supplier's lead timeA section each week
Consumable storesPurchase costA simple minimum levelMonthly

How to keep inventory types apart in ArmPOS

ArmPOS holds every type as products with stock, and categories keep the types apart. It has no production module, so work in progress isn't tracked between steps.

  1. Make a category per type, such as Raw materials, Finished goods, Goods for resale and Consumables (Categories, brands and units).
  2. Keep materials out of your online store. On each material's product, set Hide From Online Store under Options (Add your first products).
  3. Record production with two adjustments. A Subtraction takes off the materials used, and an Addition puts on the finished goods made. Put the run in the Note (Count and adjust stock). The full method is in barcodes in manufacturing.
  4. Count one type at a time. Count Stock makes a counting sheet for one warehouse and one category.
  5. Read each type's stock. The Stock Report lists each product's Current Stock with its Category, and Inventory Valuation gives each product's value at cost (Stock reports).
  6. Keep supplies out of stock. Record office and cleaning supplies as expenses, in a category such as Supplies (Record an expense). Expenses sit under Accounting, which comes with some plans only.

Frequently asked questions

What are the 3 main types of inventory?

Raw materials, work in progress and finished goods: the three stages of production. Most lists add MRO supplies as a fourth.

What are the 5 types of inventory?

The four above plus goods for resale, the stock of shops and wholesalers. Some lists count packing materials as the fifth instead.

Is MRO inventory?

Partly. Under IFRS, consumable stores and most spare parts are inventory, major spare parts are equipment, and office or cleaning supplies are expenses.

What type of inventory does a shop hold?

Goods for resale, almost only. A shop that also prepares goods, such as a butcher cutting meat, holds some raw materials and finished goods too.

Is work in progress an asset?

Yes, a current asset, valued at the materials, labour and overheads put in so far. It becomes finished goods when the work is done.

List your stock this week under the five types, with a value for each: the biggest number is where to start. To keep each type in its own category, create a free ArmPOS account.