DFC : Design for Cost

Introduction

Design for Cost (DFC) is a strategic approach within the broader spectrum of Design for Excellence (DFX), which encompasses a variety of methodologies aimed at optimizing different aspects of product design and development. DFX includes principles such as Design for Environment (DFE), Design for Assembly (DFA), Design for Manufacturing (DFM), and Design for Reliability (DFR).

DFC specifically targets a product's cost-efficiency, aiming to minimize production costs without compromising product quality or functionality. By integrating DFC principles early in the design process, companies can achieve significant savings, enhance product value, and maintain competitive pricing.

DFC and Design for X (DFX)

DFC does not exist in isolation but overlaps with other DFX methodologies such as DFA, DFM, DFR, and others. Understanding these overlaps is crucial for achieving holistic design optimization:

• Design for Assembly (DFA): DFA aims to simplify product assembly processes, reducing labor costs and assembly time. Streamlined assembly directly influences DFC by lowering production costs and enhancing efficiency.
• Design for Manufacturability (DFM): DFM focuses on designing products that are cost-effective and simple to manufacture. By considering manufacturing capabilities and constraints during the design phase, DFM ensures cost-effective production, which aligns with DFC objectives.
• Design for Reliability (DFR): DFR ensures that products are reliable and perform consistently over time. Reliable designs reduce warranty costs and enhance customer satisfaction, indirectly contributing to savings.
• Design for Environment (DFE): DFE reduces environmental impact and often leads to cost reduction through efficient use of resources and energy.

Life Cycle Cost (LCC)

Life Cycle Cost (LCC) estimation is a critical component of Design for Cost (DFC) strategies, focusing on evaluating a product's total cost of ownership throughout its entire life cycle. It includes costs incurred during the design, manufacturing, operation, maintenance, and disposal phases. Example LCC estimation strategies helpful for DFC[1]:

• Parametric Cost Method
• Analogy Cost Method
• ANN Cost Method
• ABC Method
• Engineering Cost Method

Design for Cost in the Concept Phase

The concept phase of any product design is one of the most critical steps to success. Select the proper architecture for the product. In many cases, the simpler the architecture of the product is, the cheaper and more reliable the product will be. Examples:

• Simple software architecture: Remove dependency with large and rarely used libraries. Consider writing your lightweight library or a class. Removing dependency on the external library may save a lot of costs related to licensing, software bugs, and overall maintenance issues.
• Easy firmware upgrade: Add easy firmware upgrade functionality. Use remote methods (e.g., WiFi) or a standard USB / serial interface. It will reduce the cost of product upgrades or software bug removal in the field.
• Plausibility check: Consider software methods to detect abnormal signals instead of additional hardware solutions for fault detection. This will cut down on hardware costs while still providing necessary functionality.
• Reduce hardware: Replace complex hardware boards (i.e., embedded systems with many chips, capacitors, and memories) with an advanced FPGA chip.
• Modular hardware: Use standardized modules like CPU boards, battery packs, etc - where feasible.

Most of the above examples can be considered and implemented when the design is still in the concept phase.

DFC Guidelines

Implementing DFC requires adherence to specific design guidelines aimed at cost optimization:

• Material Selection: Choose cost-effective materials that meet design requirements without over-specifying. Consider alternative materials that offer similar properties at lower costs.
• Simplified Design: Aim for simplicity in design to reduce manufacturing complexity and costs. Avoid unnecessary features that do not add significant value. Consider the TRIZ method to simplify the design.
• Standardization: Use standardized components and parts where possible. Standardization reduces inventory costs and simplifies assembly.
• Modular Design: Design products in modules that can be independently manufactured and assembled. Modular design enhances flexibility and reduces overall production costs.

Pros of DFC

• Cost Reduction: DFC leads to significant reductions in production costs, enhancing profitability.
• Competitive Pricing: Lower production costs allow for competitive product pricing, improving market competitiveness.
• Resource Efficiency: DFC promotes efficient use of materials and resources, leading to sustainable practices and cost savings.
• Improved Product Value: By focusing on cost-efficiency, DFC enhances overall product value without compromising quality.

Cons of DFC

• Initial Investment: Implementing DFC may require an upfront investment in training, tools, and process changes.
• Complexity: Balancing cost optimization with other design considerations can be complex and challenging.
• Potential Quality Trade-offs: Aggressive cost-cutting measures may risk compromising product quality if not managed carefully.

Summary

Design for Cost (DFC) is a crucial aspect of the broader Design for Excellence (DFX) framework, focusing on cost-efficiency throughout the product lifecycle. By integrating DFC principles with other DFX methodologies such as DFA, DFM, and DFR, companies can achieve comprehensive design optimization. Adhering to DFC guidelines and industry standards, organizations can realize significant savings, enhance product value, and maintain competitive market positioning. While DFC offers numerous benefits, it requires careful implementation to balance cost, quality, and functionality effectively.