This paper discusses the handling of deformable linear objects (DLOs), such as hoses, wires, or leaf springs in a polyhedral environment. It investigates the formulation of assembly or disassembly tasks based on contact states. The result is an approach that facilitates the automatic extraction of robot programs from demonstrations in virtual reality and provides a base for the parameterization of detection algorithms. For this purpose, a contact state model for the description of assembly or disassembly tasks of DLOs is presented. It is described how the contact states can be derived from a geometric model of both the DLO and the environment. Such a model may be obtained by a simulation of the manipulation tasks in virtual reality. Further, the possible transitions between the contact states are classified into general transition classes. Those transition classes enable the selection of algorithms to detect such contact state transitions.