The aim of this thesis is to study the usage of an Apparel and Footwear Environmental Assessment Tool, the Rapid Design Module, in Swedish companies in the textile and fashion industry and the tool’s possible impact on the change process of organizational culture towards a more sustainable one. A qualitative study has been conducted via interviewing and observing employees using the focal tool on-site in three different companies. A theoretical framework within organizational culture was developed along with necessary cultural traits a company should nurture in order to change its culture towards a more sustainable one. The most important findings pointed out that companies should develop common guidelines in order to use the tool in question coherently and in unison. The tool was found to act as a change initiator in the employee level of the companies and additionally management support was found to be essential in order to empower employees in taking initiative in their work. Furthermore, the tool showed signs of increased collaboration within the companies’ external and internal environments, i.e. learning from one another, as well as it was observed to encourage interdependent thinking, which both are the necessary traits mentioned earlier.