The Costing Procedure in Process Costing: A Comprehensive Guide

Think about a sugar mill, a textile unit, or an oil refinery. The raw material entering the factory gate doesn’t become a finished product in one shot – it moves through crushing, boiling, refining, weaving, or bottling before it’s ready for sale. Process costing is the accounting method built specifically for this kind of continuous, multi-stage production, and the “costing procedure” is the exact sequence of steps accountants follow to record, transfer, and finally close out costs as a product moves from one process to the next. For B.Com students, this procedure isn’t just something to memorise for exams – it’s essentially how real manufacturing units figure out what a product actually costs to make.

Why process costing needs a defined procedure 🔗

Unlike job costing, where each order or job is tracked separately, process costing deals with continuous, repetitive production of identical or near-identical units. Costs are accumulated for the entire process over a period and then averaged across all the units produced, rather than being traced to a single unit. This averaging only works if costs are recorded and carried forward in a consistent, predictable sequence. That’s exactly what the costing procedure provides – a step-by-step framework that keeps material, labour, and overhead costs moving accurately from the first process to the last, so that the final cost per unit reflects everything that went into making it.

Step 1: Debiting raw material cost to the first process account 🔗

The costing procedure begins with the basic raw material. Whatever quantity of raw material is issued to start production is debited entirely to the first process account – usually called Process I. This is because the raw material typically enters the production cycle only once, at the very start. Every process after that works on the semi-finished output handed down from the previous stage, not on fresh raw material. A separate account is opened for each process, and all expenses relating to that process are charged to it, but the initial raw material cost sits squarely with Process I.

Step 2: Charging material, labour, and overheads to each process 🔗

From here on, every process account is treated almost like a mini production unit of its own. Three types of costs typically get added at each stage:

Additional material 🔗

Some processes need extra material besides what was introduced at the start – for example, a chemical added during refining, or packaging material used near the end. This is debited directly to the process account where it’s consumed.

Labour 🔗

Wages paid to workers operating a specific process are charged to that process account. If workers move between processes, time sheets or standard allocation ratios are used to split the labour cost fairly.

Overheads 🔗

Indirect costs – power, depreciation, supervision, factory rent – rarely relate to a single process alone, so they’re apportioned using a reasonable basis such as machine hours, direct wages, or floor area. Production overheads are commonly allocated to different processes as a percentage of direct wages, though the exact basis depends on the nature of the industry.

Step 3: Crediting the process account with realisable scrap value 🔗

Production rarely goes exactly as planned. Some quantity of material is lost during processing – through evaporation, spillage, trimming, or chemical reaction. When this loss is expected and unavoidable under normal working conditions, it’s called normal loss. If this loss can be sold off as scrap – metal shavings, wastage, by-products – that realisable scrap value is credited to the process account, which reduces the net cost that has to be recovered from the good output.

Normal loss versus abnormal loss 🔗

Not all loss is treated the same way. Scrap value refers to the amount realised when the outcome of a loss is sold, even if only for a small sum, and this applies specifically to normal loss. If actual loss exceeds what was expected, the extra is called abnormal loss, and it’s costed at the same rate as good units rather than at scrap value – because it represents inefficiency, not a routine part of production. This distinction matters because normal loss quietly increases the cost per unit of good output, while abnormal loss is separated out and charged to the Costing Profit and Loss Account so it doesn’t distort the “normal” cost of the process.

Step 4: Working out total cost and average cost per unit 🔗

Once material, labour, overheads are debited and scrap value is credited, the process account gives the total net cost of that process for the period. This total is then divided by the number of good units produced (the input, adjusted for normal loss) to arrive at the average cost per unit for that process. In formula terms:

Cost per unit = (Total process cost − Scrap value of normal loss) ÷ Normal output

This average cost per unit becomes the figure used for every unit moving into the next stage, and it’s recalculated fresh for every process, every period.

Step 5: Transferring cost from one process to the next 🔗

This is the step that gives process costing its name. Costs are assigned by analysing departmental or process-wise expenses rather than tracking costs unit by unit, and the output of one process physically becomes the input of the next. Along with the physical units, their accumulated cost travels too. So Process II is debited with the cost transferred from Process I, in addition to whatever fresh material, labour, and overheads it incurs on its own. Process III then receives the combined cost from Process II, and so the chain continues.

Step 6: From the last process to the finished stock account 🔗

Once the product completes its final process, there’s nothing left to add. The finished material from one process becomes the raw material for the next, and as it’s transferred, its cost moves along until it finally reaches the finished stock account. At this point, the cost per unit calculated in the last process becomes the value at which finished goods are recorded in inventory – the same figure that later feeds into cost of goods sold when the product is eventually billed.

A simplified example of the costing procedure 🔗

Suppose a factory manufactures a chemical through two processes. Here’s how the accounts might look in a simplified form:

Here, the ₹95,000 total cost of Process I is not just a closing figure – it’s carried forward as an opening cost in Process II, on top of which fresh material, labour, and overheads are added. Process II’s output, once complete, would move to the Finished Stock Account at ₹150 per unit.

Why this procedure matters for cost control 🔗

Following this sequence isn’t just bookkeeping discipline – it gives management usable information at every stage. A rising cost per unit in one particular process, rather than an overall increase, immediately points to where inefficiency is creeping in, whether that’s excess material wastage, idle labour time, or overhead misallocation. It also supports pricing decisions, since the finished stock valuation directly affects gross profit calculations. For industries in India such as sugar, textiles, chemicals, and cement, where production genuinely does move through continuous stages, this procedure isn’t theoretical – it’s how cost accountants actually build the numbers that go into financial statements and management reports.

What do you think? If a factory skipped crediting scrap value to the process account, how would that distort the reported cost per unit? And if abnormal loss were treated the same way as normal loss, what problems could that create for a manager trying to judge process efficiency?

References

1. https://en.wikipedia.org/wiki/Process_costing
2. https://www.srcc.edu/sites/default/files/Process%20Costing%20(1).pdf
3. https://live.icai.org/bos/vcc-3rd-batch/pdf/Process_Costing.pdf
4. https://www.accaglobal.com/us/en/student/exam-support-resources/fundamentals-exams-study-resources/f2/technical-articles/process-costing.html
5. https://www.ebsco.com/research-starters/business-and-management/process-costing-accounting
6. https://www.financestrategists.com/accounting/cost-accounting/analysis-of-cost/process-costing/