Supporting customers that might not have Lean.

Lean manufacturing has come to mean a lot of different things. This can be particularly true in the EMS industry because of tradeoffs required to support multiple customers that may or may not have fully implemented Lean. This month, we focus on waste driven by the nature of EMS and ways to eliminate it.

Customer-driven constraints. “The customer made me do it” is a frequent justification for tolerated inefficiencies in the EMS world. In some cases, there really isn’t an acceptable corrective action. However, in others the inefficiency exists because the provider simply hasn’t sold the customer on the benefits of working more efficiently.

This issue needs to be addressed from both a business and a manufacturing process optimization standpoint. On the business side, forecasting methodology, optimum bond sizes and pull signals need to be mutually agreed on. On the manufacturing side, product needs to be analyzed for potential inefficiencies, and a roadmap should outline potential cost reductions over time. EPIC has developed a formally documented design for manufacturability/testability (DfM/DfT) review process that includes a detailed analysis of cost reduction opportunities and a ranking scale that “prioritizes” identified design issues by their potential cost impact. Joint EMS-customer design review meetings are held, and these working groups focus on sequential improvements that both enhance efficiency and align with customer long-term cost reduction goals. While this solution does not always completely eliminate all identified areas of inefficiency, it does provide the customer with a clear picture of what is driving unnecessary cost and a path to eliminating that cost.

Supplier-driven constraints. EMS companies face two major challenges in supply base management. First, the supply base will always have more than the optimum number of suppliers because of customer-approved vendor list requirements. Second, not all suppliers conform to the best in Lean processes.

We use a component technology review team to better address this continuing challenge. The team serves as an interface between our materials organization and process and test engineering groups. Its goal is to look at both the materials group’s requirements for best suppliers relative to quality and price, and whether or not chosen suppliers’ products are performing as specified on the production floor. This internal analysis is combined with partnering efforts with strategic suppliers. Suppliers share their current capabilities and technology roadmaps, and we share requirements and opinions on what works or could be improved relative to a given component or material. One example of this type of partnering relates to solder products. We maintain standardized processes and have teamed with a solder products supplier to better optimize its process.

The technology roadmap discussions also are shared with end-customers as part of addressing specific long-term goals such as miniaturization or increased product functionality.

Equipment constraints. Equipment strategy in EMS companies can evolve over time. Growth through acquisition can add a number of different equipment platforms. The end result can be uniquely configured production lines that are hard to balance and create significant process variation between facilities.

We have standardized companywide on our equipment and process choices with two major goals: reduce changeover time through use of flexible, easy-to-program equipment, and minimize the impact of high-mix production through broader process windows. In some cases, there has been partnering with specific suppliers to enhance existing equipment capabilities. As facilities have been acquired, excess and incompatible equipment has been rapidly redeployed or sold. The result of this standardized approach has been faster throughput, more efficient project transfers and/or multi-site builds, easier integration of acquired facilities, better utilization of manufacturing resources and the ability to quickly implement companywide process optimization initiatives.  

Personnel constraints. In a high-mix EMS environment, even the best Lean systems are challenged by variations in demand. Often the constraint is personnel-driven rather than equipment-driven. Underutilization of people resources is another form of waste. While a robust Lean system may seek to minimize production personnel, it should be doing that by building strong teams of cross-functionally trained employees who can migrate between production areas as needed.

Continuous improvement should have a strong focus on enhancing employee contributions. For example, we found that 5S philosophy was best implemented as an operator-launched, operator-driven process, rather than as a quality or management-driven process, because operators really had the best visibility into what was needed in effective policies and procedures.  CA

Ryan Wooten is engineering manager at EPIC Technologies (epictech.com); ryan.wooten@epictech.com. His column runs bimonthly.