In this thesis, an analysis of CAN-bus physical layer implementation in Volvo Wheel Loaders is made. The study addresses questions on how to achieve modular and scalable bus designs from a harness installation viewpoint. Strategies for designing systems to work for a variety of different machine configurations while minimizing part numbers and manual work in factory plants are investigated. Special consideration was taken to the regulating CAN standards to find feasible solutions that fulfills the design requirements in the standards. It was identified that modularity and scalability can be achieved in many ways. As a result of this, different solutions are presented that can be used to promote modularity and scalability of CAN-buses. The solutions are divided into sub solutions and are categorized into topology strategies and termination strategies. By combining different sub solutions when designing a CAN-bus, one can achieve different levels of modularity and scalability in their system.