**1. Introduction**

The Institute of Industrial and Systems Engineers' Body of Knowledge [1] formally defines industrial engineering as being "concerned with the design, improvement, and installation of integrated systems of people, materials, information, equipment and energy. It draws upon specialized knowledge and skill in the mathematical, physical, and social sciences with the principles and methods of engineering analysis and design, to specify, predict, and evaluate the results to be obtained from such systems."

While some authors trace the roots of industrial engineering (IE) to much earlier periods, industrial engineering began to define itself during the Industrial Revolution of the 1800s, and particularly the early 1900s. Dr. Batson's chapter, later in this book, includes a fine summary of these historical roots. Frederick Taylor (1911) developed efforts in standardization and specialization, and particularly a focus on workers, their work, and how to effectively manage them [2]. This led to the formalization of such IE sub-disciplines as production planning, scheduling, and inventory control. Nadler [3] further notes that industrial engineering has gone through three broad phases of purpose. The first, building on Taylor's initial work, focused on achieving productivity improvements (mainly efficiency0 in manufacturing plant operations. This early work established the IE profession, and lasted until the late 1920s or early 1930s. The second phase, which lasted until the mid-1980s, extended the efficiency concept with mathematical, statistical and computer-based tools [3]. These included the mathematics of engineering economics, statistics of work measurement and quality control, the modeling and optimization of operations research. As the economy transitioned to an emphasis on the service industry during the 1970s and 1980s, the same techniques and tools of manufacturing-based IE were adapted. These service workers and the systems that they work in require industrial engineering techniques to improve their productivity, just as manufacturing does.

The third phase, according to Nadler [3], shifted from "efficiency to effectiveness and quality, from relatively small systems to large or macro systems". The 20th Century saw the effective application of techniques that progressively subdivide activities to improve operations. More recently, there has been a sharp emphasis on the study of "total systems" in order to optimize operations through the integration of subsystems or parallel systems. For example, the traditional factory-centric perspective in manufacturing application shifted outward to the analysis and improvement of the entire supply chain [4]. Continued expansion and adaptation of IE principles occurred. Whereas, the supply chain once addressed the flow of parts and materials from outside sources to internal company use, supply chain

analysis has now been extended to encompass materials, services and information from raw material suppliers, through distribution centers and factories, to the final customer [5]. This establishes a value chain of activities that a firm performs in order to deliver a valuable product for the market.
