Outsourcing can be defined as transferring an activity from internal to external control. This thesis studies outsourcing in the wood product manufacturing (WPM) sector from both a customer and supplier perspective. The research design is a multiple case study approach, and it is based on six Scandinavian companies in the door, floor and window industries and one larger supplier of raw material. This study provides an understanding of driving forces for outsourcing in a different context than previously studied and has identified cost reduction in combination with reallocating resources from non-core activities as main driving forces. Compared to several other industrial sectors, outsourcing strategies for the WPM firms have little to do with accessing external sources’ capabilities. In the literature, there is often a main focus on the strategic level of outsourcing, however, such heavy resource-based focus in terms of a core competence approach in the formulation of outsourcing strategies at the customer side risks forgetting that components can still be vulnerable to supplier failure. Here, more focus needs to be put on the operational level when considering outsourcing. This thesis illustrates customers considering outsourcing where there are not any given outsourcing supplier partners developed. At the same time, for the supplier side, forward integration and specialising by taking over outsourcing is complicated by an initial divergent production flow of sawn timber. When not all contexts have developed supplier markets for directly managing outsourcing, it should not be assumed that general outsourcing models are directly applicable. In general, the question of whether or not to outsource seems too complex to simply be considered as either “in or out”. A company needs safeguards when conducting outsourcing and in a situation where there is a non-developed supplier market, parallel in-house production becomes an alternative.