This thesis focus on the investigation of material usage in the production processes of electrical motors and generators at ABB Machines, a company based in Västerås, Sweden. The study aims to understand the reasons for the occurrence of excess material after the assembly of a motor or generator and explore possible solutions to minimize its occurrence. In this study, excess material is defined as the components which was intended to be used in the final assembly of a machine but that has for some reason not been used. The components which qualifies as being defined as excess materials are components which are in the same functioning state as when they were delivered from the supplier, in other words components which has not been processed nor damaged. Further, the components defined as excess materials are only the components, after a machine has been fully assembled, which has been gathered by the production personnel working at the final assembly in pallets. For example, this can be components like screws, tube fittings and cap nuts.  The research method employed in this study was a mix of different methodologies. Five methods, a literature review, registration of materials, interviews, observations and focus groups were used to collect information and data. Thereafter, the observations, interviews and focus groups results were processed through a thematic analysis. The collected quantitative data was analysed through a quantitative analysis. With the collected and summarized information, discussions were held and conclusions were drawn regarding the research questions.  The study reveals several reasons for the occurrence of excess material in manufacturing and these include:  Substitution of material in production: Material substitutions during the production process contribute to the generation of excess material. Errors in drawing material and deficiencies in concept generation: Mistakes in the design phase and concept generation lead to the generation of excess material. Least possible order quantity exceeds the actual need: Ordering minimum quantities that exceed the actual requirements result in excess material. Problems with steering in the ERP system: Issues with the Enterprise Resource Planning system affect material management and contribute to excess material. Excess material is not a prioritized area: The management’s lack of focus on minimizing excess material leads to its occurrence. Uncertainties in stock level: Lack of accurate stock level information causes overstocking and results in excess material.  The potential solutions to address excess material in the manufacturing of electrical motors and generators can be grouped into the following categories: storage, order quantity, goods arrival structure, preparations, and general routines.  Storage: Include stocking frequently used materials, reducing the variety of items in stock to minimize substitutions, introducing specific storage locations for large projects, and implementing flexible warehousing. Order quantity: Involve trimming order quantities, improving the handling of "Dummy purchases", and splitting materials upon arrival for multiple machines in a project. Goods arrival structure: Focus on reviewing pick order sizes, establishing clearer loading systems, controlling material allocation, and synchronizing the release of pick orders. Preparations: This solution include facilitating engineering changes in production groups, streamlining part number reduction, and limiting construction items within categories. General routines: Involves checking the usability of remaining materials, collaborating with fitters and production staff to optimize processes and material choices, reporting material substitutions, and systematically tracing excess material in a database. Uncertainties in stock level: Lack of accurate stock level information causes overstocking and results in excess material.