Factory Physics is a seminal text by Professors Wally Hopp and Mark Spearman, first published in 1996. The book presented the first set of principles that systematically describe the behavior of manufacturing systems and described how these principles can be leveraged to enhance the performance of these systems. The book has been cited over 5,000 times, used as a textbook in over 200 universities in North America, and has been translated into several languages. Since its publication, the term "factory physics" and the concepts it encompasses have become standard parts of the industrial and operations management lexicons. The principles first espoused in Factory Physics have been extended to supply chains in Hopp's later book Supply Chain Science (2008) and to health care in Hospital Operations (2012).