Unfortunately, the word "system" has many colloquial meanings, some of which have no place in scientific discussion. In order to exclude such meanings, and at the same time provide a starting point for exposition we state the following definition:
A system is a set of objects together with relationships between the objects and their attributes.
Our definition does imply of course that a system has properties, functions or purposes distinct from its constituent objects, relationships and attributes.
p. 18: Italics quote cited in: Thorbjoern Mann (1992) Building Economics for Architects. p. 140 - Definition of System, 1956