This thesis will provide knowledge on how to maintain a well developed flow of material while at the same time finding an optimal level of capacities for buffers. Simultaneously, aspects that allow for positive sustainability practices will be regarded.  Buffers have a considerable impact on the performance of a production system. However, the process of optimizing buffers remains a complex task, and is therefore in need of further research. Through a thorough data collection process, simulation modeling and Multi-objective Optimization, the authors will present evidence-based recommendations for managing buffers in an optimal manner. The case company currently has two buffer zones that are to be investigated if they could be improved by finding an optimal capacity level. The current flow of material consists of certain variations in the components that will be taken into consideration, some variations need further investigation in order to be representative and applicable to this study. By applying amongst other things, Lean concepts, Gemba walks, simulation modeling, interviews and knowledge within the specific field of buffer optimization, the authors were able to provide evidence-based recommendations. These recommendations both take into account optimal buffer capacities as well as brief sustainability and economical aspects. The authors have found that one buffer zone has the potential of being removed, which will contribute to positive environmental aspects. However, if this solution is to be applied, the need of planning and managing the distribution of components is required.  Another buffer zone has been investigated by applying the concept of Multi-objective Optimization, where the objectives are to maintain high throughput while minimizing the buffer capacities. The optimization procedure generated a decrease in buffer capacities in the zone by a total of 35%. This newly acquired space can either be used for other manufacturing processes, or be discontinued, which would decrease the energy consumption and positively affect the sustainability aspect.

Detta arbete visualiserar värdeflöde av solceller vid tre olika typer av solcellsinstallationer följt av förslag till förbättring gällande ett växande installationsföretag i Sverige. Genom värdeflödesanalys kan vi se tydliga samband mellan snabb tillväxt och logistiska problem, där spårbarhet, lokaler och personal är viktiga faktorer som behöv bindas samman för att skapa ett så optimalt flöde som möjligt. Resultatet är delade i två grupper. En grupp består av visualisering och information kring hur värdeflödet ser ut och den andra av vilka förbättringsmöjligheter företaget har för sin framtida verksamhet. Vi kan också se att företaget har stor potential att öka sin lönsamhet genom att via affärssystem utveckla sin logistikhantering samt sammankoppla företagets olika instanser för att nå en mer effektiv installationsprocess. / This report visualizes the value stream of solar cells at three different types of installations, followed by proposal of improvement at a growing installation company in Sweden. Through value stream mapping, we see a clear connection between a fast growing rate and logistical problems, where traceability, facilities and staff are key factors, which needs to be connected to create as optimal flow as possible. The results are divided into two groups. The first consists of visualization and information of the current value stream and the second of what kind of improvement we suggest the company takes into consider to go even further. We can also see that the company has great potential to increase its profitability by implementing ERP to its logistical department and to connect the other departments to reach a higher level of efficiency.