The perspective of AM brings forth that it is necessary to define a complex part. In the absence of a definition, a part will be called complex when a technique will be having a problem making it. Thus, depending on the number of problems faced and techniques, there will be varying perceptions of complexity for the same part. For example, if a part consists of a section that requires a high surface finish, the part will be complex for AM but not for machining. Or if a part consists of a section that has a well-defined cylindrical cavity, the part will be complex for AM but not for drilling.