JIS

Just in sequence means components arrive at the assembly line not just on time, but in the precise sequence required for that day's build schedule. Instead of stockpiling fasteners, panels, or subassemblies in a warehouse, the supplier coordinates with the manufacturer's production schedule and delivers small batches in the order they will be used, often multiple times per day. A car plant building five different trim levels on the same line might receive door panels, seats, and wiring harnesses arranged so that when station three opens the next pallet, the first part sits ready for the next vehicle to arrive.

JIS differs from just in time, which concerns only the arrival window. A JIS supplier must sequence the shipment itself, which demands real coordination: access to the production schedule, reliable transportation, accurate tracking, and often a location very close to the assembly facility. The lead time from order confirmation to delivery typically ranges from hours to a few days, and the delivery window might be measured in minutes. This compresses supply chain slack to nearly zero, which is the point.

Variants and implementation

The practice originated in Japanese automotive manufacturing in the 1980s and is now standard in high-volume assembly environments, particularly automotive, appliance, and electronics. Some operations use milkrun deliveries, where a single vehicle collects sequenced parts from multiple suppliers on a scheduled loop. Others use point-of-use delivery, where parts arrive directly at the production station rather than a central receiving dock. Pharma and food packaging also employ JIS for products that degrade or expire quickly.

The financial burden falls on the supplier, who must invest in local warehousing, buffer inventory, and logistics infrastructure to maintain sequence accuracy while absorbing the cost of frequent small shipments. Mistakes are expensive: a missing component or wrong sequence can halt an assembly line, which costs the manufacturer thousands of pounds per minute in lost output. Quality control therefore becomes tighter, and supplier selection becomes more stringent.

Technology enablers include electronic data interchange (EDI) connections to the customer's production control system, barcode or RFID tracking at the component level, and real-time visibility platforms. Some manufacturers require the supplier to hold safety stock nearby in case of production disruption, defeating some of the inventory benefit but protecting continuity.