CONCURRENT ENGINEERING: Research and Applications Managing Complexity in Aircraft Design Using Design Structure Matrix Bharath Shekar, * R. Venkataram and B. M. Satish East point College of Engineering and Technology, Bangalore, India Abstract: Modern aerospace systems have reached a level of complexity that requires systematic methods for their design. The development of products in aircraft industry involves numerous engineers from different disciplines working on independent components. Routine activities consume a significant part of aircraft development time. To be competitive, aircraft industry needs to manage complexity and readjust the ratio of innovative versus routine work. Thus, the main objective is to develop an approach that can manage complexity in engineering design, reduce the design cycle time, and reduce the product development cost. The design structure matrix (DSM) is a simple tool to perform both analysis and management of complex systems. It enables the user to model, visualize, and analyze the dependencies among the functional group of any system and derive suggestions for the improvement or synthesis of a system. This article illustrates with a case study how DSM can be used to manage complexity in aircraft design process. The result of implementing the DSM approach for Light Combat Aircraft (Navy) at Hindustan Aeronautics Limited, India, (in aircraft design) show primary benefits of 75% reduction in routine activities, 33% reduction in design cycle time, 50% reduction in rework cost, and 30% reduction in product and process development cost of aircraft. Key Words: sequential design, concurrent engineering, design structure matrix, aerospace. 1. Introduction The aircraft design process is significantly limited in sequential design, as design of combat aircraft using sequential approach takes 4–5 years from initial concept to metal cutting as shown in Figure 1. Consequently, concurrent multiple design and development stages (concurrent engineering) are performed in parallel to reduce the lead time. In concurrent engineering, there is an early consideration for every aspect of a product’s development process. The aircraft designer in concur- rent engineering is represented by the hub of the wheel as shown in Figure 2. Communication between the designer and the other system group’s experts are indicated by the circumferential arrows. The aircraft designer presents a conceptual design of the aircraft to the system groups by use of product data management (PDM) tools, the system group’s experts comment on the design relative to his or her area simultaneously. For example, assembly experts consider assembly problems, process-planning experts consider the process sequence, and metal removal experts consider the available machine tools, new removal techniques, and so on. The aircraft designer coordinates the comments and redesign suggestions on the concept of the aircraft from each of the domain experts around the hub [1–3]. Concurrent engineering strategy focuses on the optimization and distribution of a firm’s resources in the design and development process to ensure an effective and efficient product development, however, with concurrent engineering: . The complexity of which activities to be performed in parallel and which activities to be performed sequen- tially are not defined. . Concurrent engineering hypothesis to proceed in parallel poses a severe bottleneck. In the process of proceeding in parallel, the designer must make assumptions about objects that may be the respon- sibility of another designer and related to his design context. Requiring designers to proceed with partial information, with incomplete knowledge, and sub- jective interpretation leads to bottleneck and unne- cessary rework. . Aircraft industries have followed concurrent engi- neering process without understanding the design consistency issue. The design must be optimally satisfied both internally and externally. When indivi- dual design efforts and their dependency are viewed against a collaborative context, several inconsisten- cies may result. . Aircraft design process is an evolutionary process (evolutionary processes involve the application of synchronous value engineering and other *Author to whom correspondence should be addressed. E-mail: bharath_shekar@hotmail.com Figures 1–7 and 10–12 appear in color online: http://cer.sagepub.com Volume 19 Number 4 December 2011 283 1063-293X/11/04 0283–12 $10.00/0 DOI: 10.1177/1063293X11426461 ß The Author(s), 2011. Reprints and permissions: http://www.sagepub.co.uk/journalsPermissions.nav at GEORGIA TECH LIBRARY on October 6, 2016 cer.sagepub.com Downloaded from