ABSTRACT: This paper examines the characteristics of discrete-event simulation systems in terms of their
application breadth (general or special purpose), modeling paradigm (process interaction vs. activity
scanning), and flexibility (programmable or not). Several construction simulation systems are examined
with primary emphasis on CYCLONE and STROBOSCOPE as representatives of the wide range of tools
that are currently available. CYCLONE is a well-established, widely used and simple system that is easy to
learn and effective for modeling many simple construction operations. STROBOSCOPE is a programmable
and extensible simulation system designed for modeling complex construction operations in detail and for
the development of special-purpose simulation tools. The characteristics of these systems, as well as other
recent developments, illustrate that an effective general-purpose simulation tool for construction is in
essence one based on extended forms of Activity Cycle Diagrams and the Activity Scanning modeling
paradigm. As explained through several examples, these representations are indeed the most convenient
and intuitive for construction simulation systems. Furthermore, the programmability of such a system is the
principal factor that determines its power, flexibility, and ease of learning and use.