Lean Manufacturing pipe and joint systems in practice

In lean practice, the winner is not the one who builds the best workstation, but the one who can rebuild it fastest. That is why lean pipe and joint systems — modular structures made of pipes and joints — have become the physical infrastructure of factories working in the spirit of Kaizen: they let you design a workstation, rack or trolley in the morning and, after an afternoon gemba walk, change it without a welder and without downtime. This article shows how to use them in day-to-day work on material flow.

What a pipe system is and why it has no welds

A pipe system (Pipe & Joint System, Pipe Racking System) is a modular construction system based on two elements: steel or aluminium pipes of a standardised diameter and a set of metal and plastic joints. The standard is the D28 pipe — 28 mm outer diameter, 1.0 or 2.0 mm wall — with 32 mm or 42 mm used less often. The structure is cut to size and bolted together with joints, so it is built without welding, without specialist tools and without permanently joining any elements.

The absence of welds is not a cosmetic saving but a design feature. A bolted connection can be dismantled and reassembled in a different geometry, and the same pipes and joints go back into the next project. A well-designed joint also ensures repeatability: control of the pipe insertion depth, additional securing with a self-drilling screw and an internal profile give a pull-out strength of over 80 kg — in other words, rigidity close to that of a welded structure, while remaining fully reversible. Discover the full range of components in our pipe and joint systems offering.

From Kaizen to automation: why lean pipe and joint systems are so flexible

The concept was born in Japan. In 1953, engineers at YAZAKI Kako Corporation developed a material handling system that quickly spread across Japan and the USA. Toyota, Ford and Chrysler adopted it as a tool for continuous improvement — kaizen — and since the 1990s lean pipe and joint systems have been a global standard in automotive, aerospace, electronics and logistics.

The reason is simple. Welded structures are rigid in the wrong sense: once built, they resist changes to the layout. Aluminium profiles can be expensive and require specialist assembly, and standard industrial furniture does not fit individual processes. A pipe system removes these barriers — it offers instant reconfiguration, full reusability of components, a low entry cost and the option of self-assembly by the production team. In the language of material flow design, this means one thing: the physical infrastructure keeps pace with the PDCA cycle. The layout can be improved iteratively, on the same foundation on which the Toyota Production System is built.

What you can actually build from pipes and joints

The modularity of the system only really shows in its applications. Most of the operational structures on the shop floor can be built from a single set of components.

Workstations tailored to the operator

Assembly workstations are the primary application of the system. You set the height, depth and width to suit the ergonomics of a specific operator, not the other way round — the workstation adapts to the person. When the product or the staffing changes, you rearrange the same piece of furniture in a matter of hours.

Flow racks powered by gravity

A flow rack is a gravity rack that implements the FIFO principle. Containers slide along roller tracks or plastic wheels by gravity — no motor, no power supply, no controls. This is the pure idea of karakuri, or low-cost automation: the work is done by physics, not by a drive. The empty container returns via the upper level, while the full one waits below, always in the same order in which it arrived. Any deviation from the standard is visible immediately.

Trolleys and line-side supermarkets

From pipes and joints you can build transport trolleys, kitting trolleys and tugger trolleys, and from these entire line-side "supermarkets" — set-down areas from which the milk run picks up components in line with the takt. Pallet and platform trolleys are best based on the dedicated CS system: modular chassis with drawbars and locking couplings, a diamond wheel arrangement and 360° rotation can enter even very narrow production cells. On top of this come complete assembly lines supporting one-piece flow, which you expand gradually as volume grows.

Special variants: 5S colours and ESD zones

The pipe is available in 12 colour variants compatible with visual identification systems and the 5S methodology — the colour of a workstation or container itself becomes the work standard, visible without asking and without instructing a new operator. For electronics and aerospace, a full ESD line is available: conductive pipes, nickel-plated joints ensuring continuity of conduction across the entire structure, ESD castors and ESD work surfaces. As a result, complete workstations, racks and trolleys meet the requirements of EPA zones — protection against electrostatic discharge.

Integration with milk run and AGV without replacing infrastructure

The most important feature from the point of view of factory maturity: a pipe system is designed with compatibility with AGVs and autonomous mobile robots (AMRs) in mind. Trolley and rack structures are fitted with standard coupling points, entry guides for AGV platforms and towed trolley systems, which form milk run tugger trains.

The significance of this is strategic. Today a factory can transport components with a manual milk run, and in a year's time connect an AGV platform under the same trolleys — without rebuilding the racks, without new trolleys, without replacing infrastructure. This is exactly the path "from Kaizen to automation": the modular structure grows with the process instead of forcing a costly reset at every step of automation.

How to approach implementation — a practical checklist

• Start with the flow, not the furniture. Map the material path and only then design the workstations, racks and trolleys around it.
• Design for gravity. Wherever possible, replace lifting and pushing with a FIFO flow rack — it is the cheapest automation you have.
• Standardise with colour. Assign pipe colours to zones and component families in line with 5S before you expand the hall.
• Leave room for AGVs. Even with a manual milk run, design trolleys with coupling points — a future AGV platform will slide under the existing structure.
• Treat structures as reusable. Account for components as a pool, not as one-off furniture — after every layout change they go back into circulation.

FAQ

Is a pipe system strong enough without welding?

Yes. A properly designed joint combines control of the insertion depth, securing with a self-drilling screw and an internal profile, giving a pull-out strength of over 80 kg. The rigidity is close to that of a welded structure, while the connection remains fully dismountable.

How do pipe and joint systems differ from aluminium profiles?

Aluminium profiles are rigid and look good, but they are more expensive and require precise assembly. Pipe and joint systems focus on speed of reconfiguration, a low entry cost and assembly by your own team — which is why they are better suited to environments where the layout changes frequently to the rhythm of kaizen.

Can a pipe system be combined with transport automation?

That is its intended application. Trolleys and racks are fitted with coupling points and entry guides for AGV/AMR platforms, as well as towed systems for milk run trains, which makes it possible to move from manual to automated transport without replacing existing infrastructure.