Among the solutions aimed at maintaining the integrity of part sequencing and optimizing delivery to the production line, overhead conveyors stand out. In the automotive industry, this type of conveyor plays a fundamental role in JIT/JIS logistics, as it allows bulky components to be moved and positioned efficiently without disrupting the sequential flow.
What is a Just-In-Sequence (JIS) conveyor?
A JIS conveyor is a transport system designed to move parts in a sequence, ensuring they arrive at the assembly line in the same order in which they were produced or requested. This methodology eliminates the need for manual reordering, reduces wait times, and enables production to maintain its rhythm, even in lines with high product customization.
Why choose an overhead conveyor for Just-In-Sequence production?
There are multiple technologies for sequential transport (such as guided carts, roller conveyors, or floor conveyors), but the overhead conveyor offers specific advantages when:
- Bulky parts are being handled.
- Floor space is limited.
- High design flexibility and integration with robots is required.
Additionally, since the parts are suspended, they are less likely to suffer damage or contamination during internal transport.
Ultimately, the overhead JIS conveyor allows parts to be suspended from elevated rails, freeing up floor space and ensuring that the parts’ sequence is maintained throughout the entire journey.
How overhead conveyor optimize JIS flow
Sequence preservation (guaranteed FIFO flow)
An overhead conveyor moves the hanging parts in a line, ensuring that the entry order matches the exit order. It essentially acts as a continuous rail where the sequence is preserved effortlessly. This is crucial because, as mentioned, in Just In Sequence, any disruption in the sequence requires reprocessing. By hanging the parts on a rail and moving them in order, sequential integrity is maintained during temporary storage and internal transport.
Advanced sequence management with diverts and intermediate buffers
In addition to maintaining a linear sequence, overhead conveyors enable more sophisticated flow management thanks to accessories such as diverters and intermediate buffers. These components allow the creation of branches within the circuit without the need to unload or reload the parts. The entire route is carried out with the parts hanging, following the same rail, fully automatically and without operator intervention. This makes it possible to temporarily store certain parts, perform resequencing when necessary, or feed multiple stations from a single point, without compromising the sequence or interrupting the continuous flow of the system.
Integration with the assembly line
In automotive plants, overhead conveyors typically connect different stations. A common internal JIS case is car doors transported from a robotic cell to the assembly line. Once completed by a robot, the doors are hung on an overhead conveyor that moves them in sequence to the exact point where they must be mounted on each vehicle. During the journey, the system temporarily stores the doors while preserving their order and releases them just in sequence as the corresponding body arrives at the assembly station. In this way, each vehicle automatically receives the correct doors—without manual checks or searching.
Physical link between supplier and OEM
Perhaps the most innovative aspect is that certain systems allow the overhead conveyor to extend beyond the factory and into the supplier’s facility. There are logistics solutions where the parts are hung on overhead rails that feed directly into a transport truck. Imagine a nearby Tier 1 supplier: the parts (e.g., painted bumpers) are loaded onto the overhead conveyor in the correct sequence; the same rail continues to the loading dock, where a specially equipped truck docks in such a way that the rail runs through the inside of the trailer. The parts move from the supplier’s warehouse into the truck without being unloaded or rearranged, remaining suspended and in sequence. Upon arrival at the OEM plant, the trailer’s rail connects to the overhead conveyor system of the assembly line, unloading the parts directly into the factory in the required order.
In this way, supplier and customer processes are physically linked without breaking the sequence, reducing logistics time and avoiding unnecessary handling. This type of solution is technically complex (requiring synchronized infrastructure between companies and specialized transport), but it represents the ideal of JIS: the part leaves the supplier’s line and reaches the customer’s assembly station in a continuous flow.
Space saving and ergonomics
By transporting parts overhead, floor space in production is freed up. In heavily saturated lines, not needing to place part racks at line-side is a significant advantage. In addition, parts suspended at an appropriate height can be more easily handled with assistive tools or robots, reducing physical strain for staff. Overhead conveyors can be designed with bypasses, elevators, and branches to feed multiple points, always maintaining an orderly flow.
Esypro and its technical approach to JIS overhead conveyor systems
At Esypro, we develop JIS overhead conveyor solutions tailored to the needs of each automotive plant. With over 35 years of experience in sequential logistics, we help our clients optimize their processes with robust, intelligent, and fully integrated systems.
Our solutions include:
- Design of sequenced transport systems
- Smart intermediate storage
- Synchronization with assembly lines and ERP systems
- Consulting and specialized technical support in JIS environments
Are you considering implementing a Just-In-Sequence system or looking to optimize your current one?
Contact us and discover how we can help turn your logistics into a competitive advantage.