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Design for X

Concurrent engineering is a contemporary approach to DFSS. DFX techniques are part of detail design and are ideal approaches to improve life-cycle cost, quality, increased design flexibility, and increased efficiency and productivity using the concurrent design concepts (Maskell 1991). Benefits are usually pinned as competitiveness measures, improved decision-making, and enhanced operational efficiency. The letter “X” in DFX is made up of two parts: life-cycle processes x and performance measure (ability) (Huang 1996).

The DFX family is one of the most effective approaches to implement concurrent engineering. DFX focuses on vital business elements of concurrent engineering, maximizing the use of the limited resources available to the DFSS team.

DFX tools include:

• Design for Manufacture and Assembly;

• Design for Reliability;

• Design for Maintainability;

• Design for Serviceability;

• Design for the Environment;

• Design for Life Cycle Cost;

• and so on.


DFX provides systematic approaches for analyzing design from a spectrum of perspectives. It strengthens teamwork within the concurrent DFSS environment.  The Design for Manufacture and Assembly (DFMA) approach produces a considerable reduction in parts, resulting in simple and more reliable design with less assembly and lower manufacturing costs.  Design for Reliability (DFR) enables the DFSS team to gain insight into how and why a proposed design may fail and identifies aspects of design that may need to be improved. When the reliability issues are addressed at early stages of DFSS, project cycle time will be reduced.  A simplified product can be achieved through the sequential application of DFMA followed by Design for Serviceability (DFS), which is the ability to diagnose, remove, replace, replenish, or repair any component or subassembly, to original specifications, with relative ease. Poor serviceability produces warranty costs, customer dissatisfaction, and lost sales and market share due to loss loyalty.  In Design for Life-Cycle Cost, the activity-based cost (ABC) is a powerful method for estimating life-cycle design cost to help guide the DFSS team in decision making to achieve cost-efficient Six Sigma design in the presence of market and operations uncertainty.  Another DFX family member is Design for Maintainability. The objective of Design for Maintainability is to ensure that the design will perform satisfactorily throughout its intended life with a minimum expenditure of budget and effort. Design for Maintainability, DFS, and DFR are related because minimizing maintenance and facilitating service can be achieved by improving reliability.  Design for the Environment (DFE) addresses environmental concerns as well as post-production transport, consumption, maintenance, and repair. The aim is to minimize environmental impact, including strategic level of policy decision-making and design development.