What is just-in-sequence?
The just-in-sequence (JIS) procurement method ensures that the right goods are available at the right time, at the right place and in the right sequence. This form of procurement logistics is also called in-line vehicle sequencing or sequential parts delivery. The supplier packs the appropriate parts in the right sequence so that the assembly workers can pull the right component at the right time.
Just-in-sequence is a complement to just-in-time.
The JIS process is an extension of just-in-time logistics (JIT). Unlike just-in-sequence, JIT logistics pays no attention to sequence. Both procurement methods focus on getting the goods to the right place at the right time. The just-in-time delivery method is used primarily in industrial and manufacturing companies, but is employed by some retailers as well. Its aim is to reduce inventories. JIS, on the other hand, is a more complex and involved method that only pays off once unit numbers get high.
Application areas of just-in-sequence
Just-in-sequence is particularly suited for individualised products that consist of different modules and are processed in large quantities on a production line. This is why it is used predominantly in the automotive industry, where individual car configurations are becoming increasingly important. JIS is also used by companies in mechanical engineering, aerospace and shipbuilding. Shipyards often have to install bulky components that require a large amount of space to store.
The just-in-sequence process, illustrated using the automotive sector
Car makers determine the production sequence for each car in the final assembly stage. This method is known as pearl chain sequencing. The industry is producing more and more customised cars. One production line, for example, may turn out one car with five cloth seats, aluminum rims and door modules without power windows, followed by another car with two leather seats, steel rims and power windows. For this to work, the automotive manufacturer informs the supplier via electronic interfaces (EDI) when they need to receive what quantity of which components to which assembly line and in what order – i.e. just-in-sequence.
Reasons for using just-in-sequence
Companies use JIS for several reasons:
- Stocks are not built up and so do not have to be warehoused
- Ties up less capital, especially with high-value parts
- Reduces space consumption, especially for bulky parts
- Reduces lead time, cutting costs
- Optimises production processes
- Access new markets through customisation
- More automation means fewer errors, lower staff costs
- Shifts the risk of production downtimes to suppliers
However, just-in-sequence delivery means suppliers and customers have to spend more time and energy communicating since new information about production or changeovers always have to be transferred to the supplier's system via EDI. Also, deliveries may be delayed by accidents or inclement weather. That is why large industrial parks are often built around the manufacturer's site to house their suppliers and shorten transport routes.