A simple scale highlights recommended changes and benefits.

As mentioned in this space in April, an EMS provider’s facility can completely embrace Lean Manufacturing principles, but if the OEM customer’s products aren’t designed for Lean, the result is inefficiency and missed cost-reduction opportunities. In April, we focused on key cost drivers in manufacturing and test, and likely improvements that could increase throughput. This month, we look at ways EMS providers and OEMs can build a robust Dfx for Lean teaming framework.

Most OEMs find the efficiency and flexibility driven by Lean principles highly attractive. However, the greatest levels of efficiency and flexibility are achieved when products are designed for Lean. Achieving the optimum mix of best design for process and component selection for best sourcing involves cooperation among the OEM, EMS provider and the supply chain. The challenge can occur when legacy product is best served by redesign or changes to the approved vendor list. In those situations, the costs and benefits of making the change must be weighed carefully.

In the EPIC system, each customer data package is analyzed during the project launch phase using advanced product quality planning (APQP) techniques. While APQP was developed by the automotive industry, its basic philosophy makes sense for any Lean product launch process. Key points include:

• Understand customer requirements.
  
  
• Use a robust process for product design and development verification.
  
  
• Use a robust process for production process design and development verification.
  
  
• Validate both product and process.
  
  
• Use a focused product launch process with feedback, assessment and corrective action mechanisms to ensure product meets customer requirements.

The first step in this process is the design review summary. This report lists the recommendations of the Design for Manufacturing Evaluation and scores each based on relative importance. Each importance level is defined as:

• 5 – Will not build the assembly with this issue unresolved.
• 4 – Major design issues. Can build product as designed.
• 3 - Issue should be corrected. Can build product as designed.
• 2 – Minor design issue.
• 1 – Nice to have item.

With this scale, OEMs have an easy-to-use formula for evaluating the recommended changes. Likewise, the EMS provider can easily point to the benefit each recommendation would achieve. While the analysis is conducted using internal DfM and DfT guidelines optimized for the specific production environment, the foundation for those standards is based on industry-accepted guidelines, including those published by IPC.

A ranking system doesn’t necessarily eliminate a customer response of “if I don’t make the change, how much will it cost,” but it does help focus DfM/DfT recommendations in a cost/benefit framework from the start and prioritize discussions on critical recommendations. As with any other EMS-developed tool, its actual value in reducing total cost is often determined by the customer’s willingness to accept the recommendations.

Optimum Sourcing

Another area of potential challenge can be raw material sourcing. As mentioned in April, permitting the EMS provider to source small chip components through a master AVL can be beneficial. Similarly, minimizing use of sole-sourced parts or non-returnable, non-cancellable (NCNR) parts also contributes to reduced cost.

Ultimately, it is desirable to design-in component sources willing to embrace Lean stocking principles. This is where a strong design partnership between an EMS provider and OEM can be invaluable because, while the OEM team may understand the best component choices for form, fit and function, the EMS team may have experience with which of those AVL choices are willing to support Lean practices, such as:

• Willingness to support short cycle times, flexible lot sizes and high quality.
  
  
• Ability to ensure adequate stock based on forecast while delivering to pull signals vs. requiring firm release dates over an extended lead-time.
  
  
• Willingness to maintain appropriately sized material buffers in close proximity to the production facility.

While tradeoffs are inevitable, a focus on analyzing optimum AVL choices in the design phase can help minimize the potential for raw material flow disruptions.

Ensuring optimum design for Lean is not always possible. Product design constraints such as packaging, ergonomics and regulatory restrictions can be prohibitive to Lean manufacturing principles. However, approaches that analyze key cost-drivers related to production and logistics throughput can identify potential problem areas to be addressed immediately on current product or over time (e.g., the next-generation designs).

In EPIC’s experience, Lean’s greatest cost-reduction benefits often come over time, as legacy product is superseded by product designed for Lean processes. Cost savings typically are based on a combination of improved quality, reduced factory cycle times, increased scheduling flexibility and a decrease in raw material and finished goods inventories. Achieving these benefits is a team effort among the OEM, EMS provider and supply base, and often involves compromise relative to standard practices. The more proactive the approach, the faster the benefits associated with Lean implementation can accrue. Success in this area involves defining requirements for optimum throughput, quality and schedule flexibility, and then encouraging each partner to work to apply their expertise in achieving the desired goals. The result of this cohesiveness is priceless.

Chris Munroe is director of engineering at EPIC Technologies (epictech.com); chris.munroe@epictech.com. His column appears bimonthly.

• Prev
• Next