A harness drawing is generated from the harness 3D model by "flattening" the topology. 2 methods are provided: a harness can be flattened by an automatic algorithm in one step. The second method allows the user to interact with the algorithm and to flatten the drawing step by step. This collaboration is the favorite method for bigger harnesses (more than 3o bundle segments) as it allows combining user's experience and imagination with performance and exactness of algorithm.