Bakgrund och problemdiskussion: Lagerstyrning är olika aktiviteter som rör hur ett lager hanteras och styrs. Styrningen av ett lager har en stor påverkan på ett företags lönsamhet då det hanterar de aktiviteter som berör lager och därmed också det bundna kapitalet. Lagerstyrning är dock inget som görs i en handvändning, utan det är många delar som ska stämma överens. Lagerstyrningen blir än mer komplex när företag handlar med volatila råvaror. När det kommer till lagerstyrning av produkter med volatila inköpspriser är det viktigt att ta hänsyn till dessa förändringar, för att på så sätt kunna hitta den mest optimala lagerstyrningen. Syfte: Syftet med denna studie är att undersöka vilka konsekvenser som uppstår av att Alutrade inte tar hänsyn till volatila inköpspriser i sin nuvarande lagerstyrning, samt att identifiera vilka lagerstyrningsmetoder, och därmed lagerstyrningspolicy som är lämplig att tillämpa när inköpspriser är volatila för att optimera och uppnå en kostnadseffektiv lageromsättningshastighet. Metod: Uppsatsen behandlas utifrån ett positivistiskt synsätt och ett deduktivt angreppssätt. Uppsatsen har en kvalitativ forskningsmetod men innehåller både kvalitativ och kvantitativ data. Datan har samlats in genom ostrukturerade och semistrukturerade intervjuer, samt mailintervjuer. Resultat: Eftersom Alutrade i dagsläget inte tar så stor hänsyn till de prisförändringar som råder på aluminium marknaden uppstår en del konsekvenser, vilket gör att företagets lagerstyrning påverkas negativt. För att undvika dessa konsekvenser har en lagerstyrningspolicy, som tar hänsyn till volatila inköpspriser, tagits fram. Denna policy utgår från en ABC-klassificering och innehåller lagerstyrningsmetoder såsom modifierad EOQ, beställningspunktsystem vid volatila inköpspriser, säkerhetslager som ett uppskattat antal dagars medelefterfrågan och säkerhetslager beräknat från önskad servicenivå. Med hjälp av den framtagna lagerstyrningspolicyn kan Alutrade undvika konsekvenserna och uppnå de kostnadsbesparingarna som påvisas. / Background: Inventory control is different activities related to how a warehouse is managed. The management of inventory has a big impact on a company's profitability as it manages the activities that concern the inventory and thus has an affect on the tied up capital. However, inventory control is nothing that can be rushed through, since many activities must match. The inventory control becomes even more complex when companies deals with volatile raw materials. When it comes to inventory control of these types of products, it is important to take these changes into account, in order to find the most optimal inventory control. Purpose: The purpose of this thesis is to investigate which consequences that occurs when Alutrade does not take volatile purchase prices into account, furthermore to identify which inventory control methods, and thus inventory control policy, that is suitable to apply when purchase prices are volatile to optimize and achieve a cost-effective inventory turnover. Method: The thesis is based on a positivistic and deductive approach. The study has a qualitative research method but contains both qualitative and quantitative data. The data has been collected through unstructured and semi-structured interviews, as well as mail interviews. Results: As Alutrade currently does not take the price volatility on the aluminum market into much account a number of consequences arise, which means that the company's inventory control is negatively affected. In order to avoid these consequences a inventory control policy, which takes the price volatility into account, has been developed. This policy is based on an ABC classification and contains inventory control methods such as modified EOQ, reorder point system for volatile purchase prices, safety stock as an estimated number of demand days and safety stock calculated from a desired service level. Using the developed inventory control policy, Alutrade can avoid the consequences and achieve the cost savings that are shown.

There has recently been an increased interest in hydrogen, both as a solution for seasonal energy storage but also for implementations in various industries and as fuel for vehicles. The transition to a society less dependent on fossil fuels highlights the need for new solutions where hydrogen is predicted to play a key role. This project aims to investigate technical and economic outcomes of different strategies for production and storage of hydrogen based on hydrogen demand and source of electricity. This is done by simulating the operation of different systems over a year, mapping the storage level, the source of electricity, and calculating the levelized cost of hydrogen (LCOH). The study examines two main cases. The first case is a system integrated with offshore wind power for production of hydrogen to fuel the operations in the industrial port Gävle Hamn. The second case examines a system for independent refueling stations where two locations with different electricity prices and traffic flows are analyzed. Factors such as demand, electricity prices, and component costs are investigated through simulating cases as well as a sensitivity analysis. Future potential sources of income are also analyzed and discussed. The results show that using an alkaline electrolyzer (AEL) achieves the lowest LCOH while PEM electrolyzer is more flexible in its operation which enables the system to utilize more electricity from the offshore wind power. When the cost of wind electricity exceeds the average electricity price on the grid, a higher share of wind electricity relative to electricity from the grid being utilized in the production results in a higher LCOH. The optimal design of the storage depends on the demand, where using vessels above ground is the most beneficial option for smaller systems and larger systems benefit financially from using a lined rock cavern (LRC). Hence, the optimal design of a system depends on the demand, electricity source, and ultimately on the purpose of the system. The results show great potential for future implementation of hydrogen systems integrated with wind power. Considering the increased share of wind electricity in the energy system and the expected growth of the hydrogen market, these are results worth acknowledging in future projects.