This is a master thesis research on how to select the right components in a product, considering reducing the weight with topology optimization (TO) and adaption for additive manufacturing (AM). It is well established that manufacturing of complex structures can be achieved with AM, the possibility of integrating assembled components and improve features will therefore be investigated. The new component structure must still withstand the loads that it is subjected to during usage, to not permanently deform or break. In this research the studied product was a handheld Husqvarna chainsaw. Initially a feasibility study was conducted, where the product was disassembled and physically investigated for potential component cases. Additional knowledge was gathered with one semi structured interview per case, with experienced design engineers. Followed by one semi structured interview with AM experts, regarding available AM technique and similar material. Selection of case to continue with was based on the interviews information and Pughs decision matrix, with weighted criterions. TO were used for finding the optimal material distribution. The new component design was analyzed with linear finite element analysis to fulfill both the component and material stress requirements. Component orientation and support structure for AM was analyzed with computer aided engineering software. This resulted with integrating thirteen components for the engines cylinder into one component. The new design resulted in a weight reduction of 31%, while utilizing only 57% of the allowed stress limit. Also, the first 23 natural frequencies were improved with a new type of cooling fin structure, with an increased area of 15%. These results encourage the thesis workflow methodology usage for other products. In conclusion the established workflow of methods resulted in selecting a suitable case for integrating components with feature improvement and adaption of the new design with TO for AM, to reduce the weight.