Successful purchasing processes has become an increasingly important part of keeping companies competitive. At the same time, it is common for managers to prioritize their core operations and let the purchasing process fall behind. In order to ensure that the purchasing processes works well, one can choose to hire a management consultant who can help the company identify issues and improve its purchasing process at an expert level. The key purpose of this study is to investigate, through interviews with management consultants, the way they work to help companies improve their purchasing processes. Their working methods are then compared with the theory section consisting of purchasing theory to see if there is any research missing within the subject. We have found through our interviews that there is no general process for these purchasing consultants. How they work is largely based on how developed the purchasing function is. Their way of working is in line with existing theory where the existing theory says that every challenge requires a custom solution. There are similarities in how they use theoretical models where some are used more often than others. Based on our research, we suggest that further research is needed within the purchasing process, its components and the usage of models and their impact. Both to give companies a chance to be able to make improvements before a management consultant is required, and for management consultants to be well prepared for any problems that may arise and how they can be remedied.