Complexity in engineering design and manufacturing (original) (raw)

2012, CIRP Annals - Manufacturing Technology

Increasing complexity continues to be one of the biggest challenges facing manufacturing today. It is manifested in products and manufacturing processes as well as company structures [162]. These systems operate in an environment of change and uncertainty. The subject of this keynote paper is related to the complexity of the artifactual world humans have created. The breadth of complexity research in engineering is reviewed for a broad readership and with particular emphasis on engineered products and manufacturing. Engineers are justly proud of the many inventions and manufacturing technologies for which they are responsible. In the past, Henry Ford's zero complexity approach to automobile production proved to be a breakthrough, with the assembly line and mass production that have revolutionised the industry. Since then, many manufacturers have attempted to compete using this model of reducing or eliminating real and perceived complexities. This as well as other reductionist approaches, which were critically successful at a period of time of the development of industrialization, have reached their limit. The methods used by engineers to design, produce, and operate systems in the mid-to late twentieth century are insufficient to deal with the challenges of the future. The fierce global competition has focused on innovation and creating high valueadded products at a competitive price in response to customer demands. The challenges facing industry now are characterized by design complexity that must be matched with a flexible and complex manufacturing system as well as advanced agile business processes. This is particularly true for manufacturers of high value, complex products that are multidisciplinary in nature. This is quite a broad category as most industrial and consumer products these days are complex. 1.1. Sources of complexity Modern complex products or equipment may have many thousands of parts and take hundreds of manufacturing and assembly steps to be produced. Most complex products and equipment now incorporate not only mechanical and electrical components but also software, control modules, and humanmachine interfaces. Some equipment is connected on-line to the World Wide Web and ''the internet of things'' [10] for real time reporting and diagnostics. Although these additions have made equipment more versatile and dependable, significant complexity has been introduced to the product design [64]. Manufacturers have often responded to the challenges of globalization with mergers, consolidations and acquisitions. Fig. 1 illustrates the drivers and enablers for manufacturing complexity. Economic, technological and social aspects are included. 1.2. Perspectives on complex systems Several different measures defining complexity have been proposed within the scientific disciplines. Such measures of complexity are generally context dependent. Colwell [27] defines thirty-two complexity types in twelve different disciplines and domains such as projects, structural, technical, computational, functional, and operational complexity. Systems complexity is invariably multi-dimensional. A complex system usually consists of a large number of members, elements or agents, which interact with one another and with the environment. They may generate CIRP Annals-Manufacturing Technology 61 (2012) 793-814