Collected Views on Complexity in Systems

The term complexity is used in many different ways in the systems domain. The different uses of this term may depend upon the kind of system being characterized, or perhaps the disciplinary perspective being brought to bear. The purpose of this paper is to gather and organize different views of complexity, as espoused by different authors. The purpose of the paper is not to make judgments among various complexity definitions, but rather to draw together the richness of various intellectual perspectives about this concept, in order to understand better how complexity relates to the concept of engineering systems. I have either quoted directly or done my best to properly paraphrase these ideas, apologizing for when I have done so incorrectly or in a misleading fashion. I hope that this paper will be useful as we begin to think through the field of engineering systems. The paper concludes with some short takes -- pungent observations on complexity by various scholars -- and some overarching questions for subsequent discussion