Knowledge has always been a very important and strategic element for companies, but today more than ever, being able to manage this knowledge is the cornerstone of success. Indeed, in a world increasingly competitive and changing, knowledge management creates value and gives a competitive edge. For this purpose, knowledge management is a major component in ensuring the sustainability of companies. Knowledge is a company's legacy and can be an irreplaceable resource; however, many risk factors, including the retirement of employees, work reorganization, or changes of positions can result in the loss of knowledge available. Therefore, identifying all of the knowledge and know-how in a company becomes a high-stakes challenge. One of the first steps of the knowledge management process is called knowledge mapping. This is a tool that helps us visualize the know-how within a company. Knowledge mapping allows performing an analysis that determines the useful knowledge that needs to be preserved, perpetuated, and shared. Thus, knowledge mapping guarantees the sustainable development of companies over time. This paper presents a project for the implementation of knowledge mapping. The study was performed at The Laboratory of Medical Analysis and Research of the Fraternal of the Royal Gendarmerie in Mororcco (LRAM). The knowledge mapping was performed using a domain approach. A domain of knowledge can be defined as the field of activity of a group of people for which information and knowledge can be grouped (Aubertin 2007, p.135).Then, the criticality of the identified knowledge was evaluated in order to retain the critical of it. Afterwards, we conducted a strategic analysis to compare the critical knowledge domains with the strategy axis of the LRAM. As a result, an action plan was established to ensure the transfer and preservation of critical and strategic knowledge.