In this paper, we discuss how to establish profiles of system engineering standards for companies. To define an appropriate system engineering standard for a company, this paper presents a detailed comparison between the current releases of the main system engineering sta-ndards (ANSI/ EIA-632, ISO/IEC-15288 and IEEE-1220), and explains how to choose the most adapted one according to the company practices. When no standard completely corresponds, the paper illustrates how to elaborate a tailor-made standard on the basis of specific required characteristics of the company or of the project, following a multi-standard approach, leading to extend and adapt a sta-ndard by importing some elements from another.