Delft University of Technology
Faculty Mechanical, Maritime and Materials Engineering
Transport Technology / Logistic Engineering



G.J.S. Vroege Just-in-time in de externe toelevering.
Literature survey, Report 92.3.LT.3022, Transport Technology, Logistic Engineering.


The Japanese have implemented with success Just-in-Time purchasing. Western companies who aim to implement JIT purchasing must know there is a cultural difference in relationships between companies. In Japan the suppliers are ruled by the buying companies. In the West relationships must be based on cooperation.

In Western countries the model of JIT purchasing consists of five elements. Tactical planning is the first. In this element the central issue is the relationship between buying company and supplier. The other four elements are part of the operational planning. These are: data flow, material flow, shipping agent and quality management.

To achieve cooperation both parties must trust each other. Qualitative factors provide this trust. Good supplier programs and a solid intention determine the qualitative factors. A supplier program informs the suppliers. The buying company proves to have a solid intention by working seriously on: relation management, contract, cost calculation and rationalism.

Quantitative factors support qualitative factors. Those are all agreements put in the frame contract.

The data flow to the supplier consists the planning information and direct delivery demand. Electronic Data Interchange (EDI) is used for the data exchange.

High-value parts are chosen for JIT purchasing. The supply frequency is based on minimal costs of transport and stockholding.

The shipping agent overtakes the logistic function of the supplier and buying company. The shipping agent has to combine freights in order to optimize the material flow. He also manages the central warehouse for not-JIT parts.

Quality management contains five elements: quality planning, quality control, quality testing, quality adjusting and securing quality costs. The buying company determines the planning aims. The supplier is responsible for the product quality. Both parties are responsible for product testing. Statistical methods must be used in this testings. The buying company evaluates the quality adjusting as part of the quality management. The aim of securing costs is reducing the total quality costs. Quality costs are costs of failure, costs of prevention and judgement costs.


Reports on Logistic Engineering (in Dutch)
Modified: 2000.07.29; logistics@3mE.tudelft.nl , TU Delft / 3mE / TT / LT.