This is a master thesis in Industrial design engineering at Luleå University of Technology. The project was carried out between August 2017 and January 2018. The thesis is done at Lindbäcks Bygg AB in Piteå. Lindbäcks is a manufacturer of wooden apartment buildings. The buildings are built with modules that are made in factories. In connection to the main factory in Öjebyn,there is an external production line that creates special products. This external production line is referred to the Sub-Factory in this thesis. The objective of the project is to design the Sub-Factory to meet the future needs. By investigating and analyzing the current state as well as the requirements of needs, concepts of change will be developed and presented. The project aim is to present a decision basis onhow to utilize the Sub-Factory in the future and suggestions on implementation of changes to reach the future state. A theoretical framework was established to create a scientific foundation for theproject. To create an understanding of the current state observations, interviews, and document reviewing were the main methods. The main problems were noted. The problems were analyzed to map out their underlying causes. With these problems and causes in mind, objectives of the solution were established. Conceptual solutions were then generated using creative methods such as brainstorming, layout ideation, benchmarking, and workshop. The gathering of data showed that the main problems of the Sub-Factory were that the capacity was limited, and the factory was inflexible. The underlying causes ofthese problems were: wrong or non-arriving material, faulty drawings, waiting,blocked transport aisles, and that the Sub-Factory is less prioritized than otherparts of Lindbäcks. The final results aim to fulfill the objectives of the solutions. The final solution consists of five concepts; layout, routines, machines and equipment, test runs, and production planning. The layout solution aims to solve several of the objectives by inducing shorter and more efficient flows. The other concepts aim to complement the layout so that all objectives can be fulfilled. To implement these solutions an implementation strategy has been established. The implementation strategy suggests an order of implementation and why to implement in this particular order.