Differing roles of axiomatic design and design structure matrix in reducing system complexity

Large-scale systems are often complex. A major contributing factor to their complexity is the numerous dependencies between components. Manipulating a component disrupts other components, and vice versa. This impedes system development, maintenance, and modification. To reduce system complexity, it is essential to minimize and manage these dependencies. Axiomatic design (AD) and design structure matrix (DSM) are methods that have the capability to accomplish this. Apparently, AD and DSM are similar. Both compute dependencies in matrix form to systematize dependency analysis. In reality, they are fundamentally different, and as we demonstrate below they may complement each other. AD minimizes dependencies between system functions. Many of these dependencies are caused by inappropriate system parameters, and they can be eliminated by changing the parameters. However, certain dependencies are inevitable, as they are inherent due to the laws of physics and logic. DSM can then be employed to manage such dependencies by manipulating the system parameters into a modular architecture. In short, AD eliminates avoidable dependencies, whereas DSM manages the remaining inherent dependencies. This study explicitly demonstrates the different roles of AD and DSM in reducing system complexity. We used a mechanical system as a hypothetical case study.