Sustainable development is important and companies are to a greater extent considering actively working to contribute to sustainable development. There are many driving forces for working with sustainability issues, but such initiatives are not always implemented. Examples of such driving forces may be market positioning or laws and requirements. To facilitate a shift towards sustainability, companies can use various methods and tools to lead. The purpose of the study is to introduce a tool and explain what it can look like and be used to change an organization to become a sustainable one. The tool in question is a carbon budget and previous research shows that there are not many studies done on carbon budgets at company level, even though it is relatively well used at region or country level. To answer the research question, a qualitative case study has been conducted where the empirical data sources consist of an interview study and observations. The case study was conducted at a manufacturing company in the electronics industry.The study through the case study succeeded in identifying a number of factors that are judged to have an impact on the success of a carbon budget as a tool. Above all, the study demonstrates the importance of being able to measure the emissions that exist as it is central to goal follow-up and motivation. In order to succeed, a carbon dioxide budget also needs to have a good foundation in management, a good and communicated vision and an action plan for how emissions are to be reduced. Furthermore, the study identifies that a carbon dioxide budget can to a large extent interact with Lean, provided that it is constructed in accordance with the study's framework. The connection with Lean enables the budget to have a greater focus, but also good help from the tools that Lean contains to work with reducing the "waste" of carbon dioxide emissions.Overall, the study believes that it is important from a strategic point of view to work with sustainability issues and a carbon dioxide budget is a good tool for that. The study thus makes a contribution to both research and the planet by further showing opportunities for companies to do something for the climate.