<XML><RECORDS><RECORD><REFERENCE_TYPE>0</REFERENCE_TYPE><REFNUM>8819</REFNUM><AUTHORS><AUTHOR>Johnson,C.W.</AUTHOR></AUTHORS><YEAR>2006</YEAR><TITLE>What are Emergent Properties and How do They Affect the Engineering of Complex Systems?</TITLE><PLACE_PUBLISHED>Reliability Engineering and System Safety Journal, Volume 91, Number 12,</PLACE_PUBLISHED><PUBLISHER>Elsevier Science</PUBLISHER><PAGES>1475-1481</PAGES><LABEL>Johnson:2006:8819</LABEL><KEYWORDS><KEYWORD>emergence</KEYWORD></KEYWORDS<ABSTRACT>‘Emergent properties’ represent one of the most significant challenges for the engineering of complex systems. They can be thought of as unexpected behaviors that stem from interaction between the components of an application and their environment. In some contexts, emergent properties can be beneficial; users adapt products to support tasks that designers never intended. They can also be harmful if they undermine important safety requirements. There is, however, considerable disagreement about the nature of ‘emergent properties’. Some include almost any unexpected properties exhibited by a complex system. Others refer to emergent properties when an application exhibits behaviors that cannot be identified through functional decomposition. In other words, the system is more than the sum of its component parts. This paper summarizes several alternate views of ‘emergence’. The intention is to lend greater clarity and reduce confusion whenever this term is applied to the engineering of complex systems.</ABSTRACT><URL>http://www.dcs.gla.ac.uk/~johnson/papers/RESS/Complexity_Emergence_Editorial.pdf</URL></RECORD></RECORDS></XML>