What high-mix, low-volume production is — the structural problem in Japanese manufacturing, and where the answers lie
High-mix, low-volume production: production methods that cope with variation, joined to new technology
What this article covers
High-mix, low-volume production is talked about constantly in Japanese manufacturing these days. Why is this form of production drawing attention, what lies behind it, and how should it be handled? This article looks at the structural problems on the factory floor, at what high-mix low-volume production actually looks like and what can be done about it, and at the trap of letting the technology become the goal.
Why high-mix, low-volume production is increasing
- Customers want different things: consumers have shifted from a lot of the same thing to the thing that suits them.
- Production has gone global: volume production, which needs relatively little production-management resource, has moved to overseas sites that are cheaper, while small-lot, high-value products that are hard to make efficiently abroad have become the centre of gravity in Japan.
- The nature of smaller companies: small firms with few people and a lot of flexibility are often strong at per-customer specification changes and at handling many variants, so they end up carrying a high proportion of high-mix, low-volume work.
- Domestic sites as mother plants: more and more, domestic sites are used to develop production engineering and to work products up during launch, with the know-how then taken to overseas plants.
The numbers, and where it is going
Several surveys make clear that high-mix, low-volume has become the de facto standard in Japanese manufacturing, particularly among smaller firms.
A national survey of small and medium manufacturers
In a survey of more than 1,000 small and medium manufacturers across Japan by the Japan Institute for Labour Policy and Training (JILPT):
- Companies answering “mainly high-mix, low-volume”: 478
- Companies answering “mainly volume production”: 225
→ About 60% describe their production as mainly high-mix, low-volume — more than twice the proportion that is mainly volume production.
[Source: JILPT, survey report on human resource development and skill transfer in small and medium enterprises (2013)]
A survey of smaller firms in the Kitakyushu area
A survey of small and medium manufacturers in the Kitakyushu area by the University of Kitakyushu found:
- Companies where high-mix, low-volume products are 71% or more of their sales: 40.0%
- Companies where the figure is 30% or less: 34.6%
→ At regional level too, high-mix, low-volume production is at the core of sales for a great many firms.
[Source: University of Kitakyushu repository, an analysis of high-mix low-volume production in regional small and medium enterprises (2017)]
Where policy stands
The White Paper on Manufacturing Industries published by METI also states plainly that the ability to handle this kind of production is essential to the survival of Japanese manufacturing.
With per-customer specification changes and a shift to higher-value products both being asked for, building a flexible production system — and securing the technology and the people to support it — is named as the task ahead.
[Source: METI, White Paper on Manufacturing Industries (meti.go.jp)]
High-mix, low-volume is no longer a special case; it is one of the mainstreams of Japanese manufacturing. Among smaller manufacturers especially, the shift has happened naturally for practical reasons: a wider variety of orders, and the need to respond quickly to what customers ask for.
Production methods that support it
High-mix, low-volume production brings problems of its own: more changeover time, holding quality steady, making people multi-skilled. Below are two methods, with examples of Japanese companies actually using them — the company, the product category, why they adopted it, and what came of it.
1. Mixed-model production: several variants running down one line
Mixed-model production runs several kinds of product down a single line, one after another. In Japanese manufacturing the examples are led by the automotive industry.
- Toyota: mixing power sources and body types (automotive)
At Toyota’s Motomachi plant, saloons, SUVs and MPVs, and petrol, hybrid, battery-electric and fuel-cell vehicles, run mixed down one line, achieving both flexibility and equipment utilisation. - Mazda: high-frequency mixing through planned-sequence production (automotive)
Assembly sequence is managed one vehicle at a time against customer orders, with parts suppliers tied into the same sequence, giving short lead times at high precision. A pioneer, working on mixed-model production since the 1960s. - Canon: mixed-model production on a common line design (office equipment)
A common assembly line, the ONE line, brought changeover under 60 seconds. Equipment and jigs were standardised, allowing many variants in parallel; productivity rose 4.3 times.
2. Cell production
In cell production, one worker or a small team takes on several processes and assembles the product through to completion. Many Japanese companies have adopted it, both for handling high-mix low-volume work and for using and developing workers’ skills.
- Casio (digital cameras, watches)
Adopted dynamic cell production, with one worker covering several processes, cutting inventory, shortening lead times and allowing the line to be reconfigured flexibly. - Sony GMO, Kosai site (professional video equipment)
A very high-mix line producing as many as 100 kinds of product a month. Work guidance such as E-Assy holds quality and productivity together. - Kyocera (electronic components)
Modular equipment for productivity, and multi-skilling through training, cutting changeover time and allowing the layout to be changed flexibly.
Both methods are effective ways of raising productivity, flexibility and the use of people’s skills in an age of high-mix, low-volume production, and both are adopted and tuned according to volume, the number of variants, and the realities of the floor.
Technology that supports it
The underlying technologies sort into three: cutting the time spent not making anything, supporting efficient production, and removing dependence on particular individuals.
| Aspect | The problem | Examples |
|---|---|---|
| Cutting the time spent not making anything | Shortening non-running time: changeover, adjustment, waiting on the schedule |
|
| Supporting efficient production | Holding quality and productivity with few people and short lead times |
|
| Removing dependence on individuals | Reducing work and judgement only one person can do |
|
These technologies move quickly, so choosing them and reviewing the choice periodically matters. Generative AI in particular has had a large effect, and technology is now appearing for areas that used to be out of reach. With more options available, the ability to judge what your own company genuinely needs matters more than ever.
Beware of letting the means become the end
A common pattern: a dashboard built for the sake of visibility, an AI visual inspection system bought for the sake of using AI — the adoption of the technology becoming the goal.
To avoid it, be clear about which of quality, delivery and cost you want to improve, understand the gap between the ideal and where you are, and then ask which technology closes it.
In closing
High-mix, low-volume is an unavoidable reality in Japanese manufacturing. Handling it takes care in the production method, use of technology, and management that does not lose sight of the purpose.
Technology is a tool. Be clear about the purpose, and adopt the technology that fits it, in the smallest amount that will do. That balance is what makes a factory floor strong.
