ARGESIM Benchmark C14 ‘Supply Chain Management' allows different modelling approaches, from classical simulation approaches with discrete event sys-tems or process modelling to directly programmed system evaluation. The tasks require a classical feedforward planning mechanism, without implicit feedback loops. An intrinsic property of the supply chain is a bi-directional flow, a material flow from factory via distributor to wholesaler, and an order flow from wholesaler via dis-tributor to factory. Some simulation systems provide special modules for supply chain integrating these bidi-rectional flows, otherwise ‘twin’ modules must be defined, with reverse flow and intracommunication. Directly programmed modules for the flows may be an efficient approach, but the model flow descriptions are hard to read and not really suitable for understanding of the process. This solution tries an alternative approach using a fully object-oriented modelling approach for the modules fatory, distributor, and wholesaler – defined in MATLAB in order to make use of efficient vector and matrix structures.