EnglandDesign and TechnologySyllabus dot point

What are the scales of production, and how do they affect tooling, cost, automation and stock control?

The scales of production (one-off or bespoke, batch, mass and continuous), their use of jigs, fixtures and automation, the relationship between fixed cost, volume and unit cost, and Just in Time (JIT) stock control.

A focused answer to OCR A-Level Product Design on the scales of production: one-off (bespoke), batch, mass and continuous production, the use of jigs, fixtures and automation, the calculation of unit cost from fixed and variable costs, and Just in Time stock control.

Generated by Claude Opus 4.812 min answerUpdated 2026-06-02

Reviewed by: AI editorial process; not yet individually human-reviewed

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Quick answer

There are four scales of production. One-off (bespoke) makes a single unique product to a client's needs (a tailored suit, a prototype); it uses skilled labour, has high unit cost and is flexible. Batch makes a set quantity of identical products, then resets for another product; it uses jigs and fixtures for consistency and has medium unit cost. Mass makes very large numbers of identical discrete products on an automated line (cars, kettles); it has high tooling cost but low unit cost and low flexibility. Continuous runs non-stop to make a bulk commodity (paper, steel, drinks); it is highly automated and costly to stop. The economic rule is that total unit cost is the fixed (tooling) cost shared per unit plus the variable cost, so high-tooling processes only beat low-tooling ones above a break-even volume. Just in Time (JIT) stock control delivers parts exactly when needed, cutting storage cost but relying on dependable suppliers.

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What this dot point is asking
The four scales of production
Jigs, fixtures and automation
The economics: fixed cost, volume and unit cost
Just in Time stock control

What this dot point is asking

OCR wants you to define the four scales of production, link each to its tooling, automation and stock control, and use the relationship between fixed cost, volume and unit cost to judge which scale suits a product. Scale is the hinge between the design and the economics of making it.

The four scales of production

Key fact

One-off (bespoke) production makes a single, unique item to a specific requirement (a bridge, a wedding dress, a prototype); it needs highly skilled labour and general-purpose tools, is very flexible, but has the highest unit cost. Batch production makes a defined number of identical products as a batch, then the equipment is reset for a different product; jigs and fixtures make the batch consistent, and the unit cost is moderate. Mass production makes very large numbers of a discrete product on a dedicated, automated line; tooling cost is high but spread over so many units that the unit cost is low, at the price of low flexibility. Continuous production runs non-stop, often 24 hours a day, to make a commodity in bulk (paper, glass, petrol); it is highly automated and very expensive to start or stop.

The discriminator between mass and continuous is the product: mass makes discrete, countable products (cars), while continuous makes a flowing commodity (paper from a roll).

Jigs, fixtures and automation

Jigs, fixtures and automation are how a manufacturer turns a one-off skill into a repeatable, scalable operation, which is why they appear in batch and mass production.

The economics: fixed cost, volume and unit cost

This relationship is why scale and process are inseparable, and why Component 01 sets calculation questions that ask you to find a unit cost or a break-even volume before judging which scale to use.

Just in Time stock control

Finding the break-even volume between two processes

Write the cost of each process

Process A (injection moulding) has a fixed tooling cost of $30{,}000$ pounds and a variable cost of $2.00$ pounds per unit, so its total cost for $n$ units is $30000 + 2.00n$ . Process B (batch machining) has negligible tooling and a variable cost of $5.00$ pounds per unit, so its total cost is $5.00n$ .

Set the two totals equal

At break-even the totals match: $30000 + 2.00n = 5.00n$ .

Solve for the volume

Rearrange: $30000 = 5.00n - 2.00n = 3.00n$ , so $n = \frac{30000}{3.00} = 10{,}000$ units.

Interpret the result

Below 10,000 units the low-tooling batch process is cheaper; above 10,000 units the moulded mass process is cheaper. Always state which side of break-even the expected demand falls on, because the judgement, not the number, earns the application mark.

Exam-style practice questions

Practice questions written in the style of OCR exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

OCR 20204 marksDefine batch production and define continuous production, and for each give a suitable product.

Show worked answer →

A Component 01 recall question. One mark for each definition and one for each product.

Award marks for: batch production makes a limited, specified quantity of identical products (a batch), after which the line or machinery is reset to make a different product; jigs and fixtures are used so the batch is consistent. A suitable product is a run of a particular furniture model, a print run of books or a seasonal range of clothing. Continuous production runs non-stop, often 24 hours a day, to make a commodity in very high volume; it is highly automated and expensive to stop and start. A suitable product is paper, steel, glass, petrol or bottled drinks.

A common dropped mark is confusing mass and continuous: mass production makes large numbers of a discrete product (cars, kettles), while continuous production runs without stopping for a bulk commodity.

OCR 20228 marksA company expects to sell 50,000 of a new product per year. Tooling for injection moulding costs 40,000 pounds and each unit costs 1.50 pounds in materials and labour. Calculate the total unit cost over the first year, and evaluate whether mass production with this tooling is justified compared with a low-tooling batch process at 4.00 pounds per unit.

Show worked answer →

A Component 01 calculation and evaluation question, marked by levels with credit for the working.

Calculate first. Fixed (tooling) cost shared per unit is $\frac{40000}{50000} = 0.80$ pounds. Total unit cost = fixed share + variable cost = $0.80 + 1.50 = 2.30$ pounds. Compare with the batch alternative at $4.00$ pounds per unit (low tooling, higher variable cost). At 50,000 units the moulded route ( $2.30$ ) is cheaper than the batch route ( $4.00$ ), saving $1.70$ per unit, about $85{,}000$ pounds a year. Evaluate: mass production is justified at this volume because the high tooling cost is spread thinly and the low variable cost dominates; the break-even volume is where $\frac{40000}{n} + 1.50 = 4.00$ , giving $n = \frac{40000}{2.50} = 16{,}000$ units, so above 16,000 units a year the moulded route wins. The conclusion should note the risk if demand falls below break-even, and that mass production reduces flexibility.

Markers reward correct working, the break-even reasoning and a justified conclusion, not just the arithmetic.

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Sources & how we know this

OCR A Level Design and Technology (H404-H406) specification — OCR (2017)