Complex systems are challenging for engineers. In considering the challenges in addressing com-plex problems as well as designing and developing complex systems, the INCOSE Complex Sys-tems Working Group (CSWG) Heuristics Focus Team, in conjunction with the INCOSE Heuristics Team, has considered a range of systems engineering heuristics that guide the engineering of complex systems. These heuristics provide some initial insight for understanding the engineering of complex systems. This work aims to identify, develop, analyze and curate these heuristics and their potential use in dealing with complexity and developing complex systems. This paper con-cludes that a range of beneficial heuristics have been identified that cover the breadth of complex problems, as assessed from multiple perspectives. This initial or preliminary set of heuristics needs to be tested through practice and use across the INCOSE community before effort is expended to make them more memorable either individually or as a set.