Conducting large-scale complex modeling and simulation (M&S) projects continues to pose significant challenges for M&S engineers, project managers, and sponsoring organizations. This advanced tutorial presents an M&S life cycle to alleviate the challenges. The M&S life cycle describes a framework for organization of the processes, work products, quality assurance activities, and project management activities required to develop, use, maintain, and reuse an M&S application from birth to retirement. It provides guidance to an M&S developer (engineer), manager, organization, and community of interest. The M&S life cycle specifies the work products to be created by executing the corresponding processes together with the integrated verification, validation and quality assurance activities. The M&S life cycle is critically needed to modularize and structure a large-scale M&S application development, and to provide valuable guidance for conducting an M&S project successfully.