What it means
When you run a business that makes physical products, your inventory usually sits in three buckets: raw materials waiting to be used, work-in-process items currently being built, and finished goods ready for customers. Work-in-process sits right in the middle of this operational journey.
From an accounting perspective, this category matters because it ties up your cash. The money you spent on raw materials and initial staff wages is now physically stuck on the factory floor.
Until those items cross the finish line and get sold, that money cannot be used elsewhere in your business. Tracking this inventory helps you spot bottlenecks in your production process.
If your work-in-process pile keeps growing week after week, it usually means your production line has slowed down or hit a snag. This buildup warns you that cash is getting trapped and delivery times might start slipping.
Managing this stage effectively requires balance. You want enough items in progress to keep your staff busy and your equipment running smoothly, but not so many that your workspace becomes overcrowded and your cash flow dries up.
Keeping a close eye on this metric ensures your production runs smoothly from start to finish.
In practice
Real-world examples.
Example
A furniture maker has ten custom dining tables currently glued and clamped in the workshop, awaiting final sanding and varnishing before delivery to clients.
Example
A local bakery has fifty unbaked sourdough loaves sitting in proofing baskets overnight, ready for the early morning ovens and subsequent shop display.
Example
A software development firm treats unfinished app code as work-in-process, representing staff hours spent building features before final testing.
Think of it
“Work-in-process is like a half-baked cake sitting on your kitchen counter. You have already bought and mixed the flour, eggs, and sugar, but you cannot serve it to guests until it spends time in the oven.
Formula
Calculation
Opening WIP + Manufacturing Costs (Direct Materials + Direct Labour + Factory Overhead) - Cost of Goods Manufactured = Closing WIP.
Example: £5,000 starting WIP + £10,000 added costs - £12,000 finished goods = £3,000 ending WIP inventory value.Case study
Seen in the real world.
Oakline Kitchens manufactures bespoke cabinets for homeowners. At the end of March, the owner, Sarah, needed to value her stock for the monthly accounts. Her records showed she started March with £4,000 worth of unfinished cabinet frames on the shop floor. During the month, she added £6,000 in raw timber and hardware, plus £5,000 in carpenter wages, bringing total production input to £15,000. By month end, her team had completed and moved £12,000 worth of cabinets into the finished goods area for delivery. Using these figures, Sarah calculated her ending work-in-process inventory at £7,000. This calculation revealed that £7,000 of her working capital was currently tied up in half-built cabinets. Seeing this high number prompted Sarah to reorganise her workshop layout to speed up assembly times and free up that trapped cash.
Watch out
Common mistakes.
- Forgetting to include a portion of labour and overhead costs in the valuation of unfinished items.
- Treating damaged or unsaleable items on the production line as good work-in-process inventory.
- Failing to update inventory records regularly, leading to huge surprises during the annual stock count.
Questions
People also ask.
How does work-in-process differ from raw materials?
Raw materials are untouched supplies waiting to be used. Work-in-process items have already had labour and materials applied to them, meaning they are actively being transformed into finished products.
Is work-in-process considered an asset on the balance sheet?
Yes. Because it costs money to buy the materials and pay staff to build them, unfinished items hold financial value and are listed as current assets until sold.
Why is having too much work-in-process a bad thing?
Excess unfinished stock ties up your cash flow, takes up valuable physical space, and often hides inefficiencies or blockages in your production line.
From the founder's library
Take it further with the book.
Build your financial confidence beyond this definition. Shihan's full-length guide, Accounting Fundamentals, takes the same plain-English approach and turns it into a complete, practical playbook for non-finance managers, business owners and students - with chapter-end quiz answers and presentation slides included.
25% off with code MMHQ25, applied at checkout. Priced in USD - checkout may show the equivalent in your local currency.
View the book and save 25%Related