Communications efficiency is oft-overlooked but can make a difference in product quality.
One area not much discussed in Lean manufacturing articles is communications with customers and its role in minimizing defect opportunities, overproduction, excess inventory and excess transport. That it isn’t talked about as widely as other aspects of Lean philosophy doesn’t suggest a lack of infrastructure driving efficient communication. Quality standards have been increasing requirements in this area for over two decades through clauses related to contract review, product quality and customer satisfaction measurements.
While communications efficiency is critical in any relationship involving configure-to-order product, it is especially important in electronics manufacturing services (EMS). EMS companies often deal with customers with widely varying requirements, and there is a need for highly organized information gathering and dissemination. That need has increased dramatically over the past few years for two reasons. First, sourcing teams at most OEMs have become younger and less experienced. That is partially a skills availability issue and partially the reflection that many OEM management teams see outsourcing as just one more supply-chain management task that doesn’t require a highly specialized team. Second, the focus on removing cost from the equation really has driven EMS companies to become an extension of their customers – aligning with their customers’ ordering systems, filling gaps in customer teams or documentation, and serving as the manufacturing expert instead of just the company that builds widgets. In short, one of the key points of value a good EMS provider brings to the contract manufacturing equation is a disciplined process that ensures the customer makes decisions on critical issues as early as possible.
From a Lean perspective, strong communications processes are critical in several areas.
New product introduction (NPI). The NPI process involves several areas where communication is critical to implementation of Lean philosophy. One such critical area is Dfx, which may include design for manufacturability (DfM), design for testability (DfT), design for assembly (DfA) and design for procurement (DfP) recommendations.
At SigmaTron, the NPI process starts with the receipt of CAD files from the customer, along with a bill of materials (BoM) and approved vendor list (AVL). DfM reviews include specific recommendations on issues to be addressed prior to production start. The report is color-coded to indicate the seriousness of the issue.
Red indicates a critical process assembly issue; yellow indicates a tooling issue; green indicates minor changes that would be nice to have, and blue indicates no change required. This helps the customer understand the impact of each recommendation.
DfT is also evaluated. The analysis includes a look at test coverage and whether the correct solder mask openings are in place. The goal is to create a robust verification process with as much coverage as possible that also considers the customer’s preferences for cost of test.
Other issues that potentially impact production cost are also evaluated as the process flow is designed. For example, a product with mixed technology may be analyzed to determine if wave solder or selective solder is most cost-effective to solder through-hole parts. This focus on developing the most efficient process flow is particularly beneficial for highly regulated products where there may be limitations on process changes once the product is in production. It also helps eliminate overproduction or overprocessing, which can occur when the automation strategy isn’t optimized to the product’s requirements.
Tools such as Gantt charts and action item logs are also used throughout the NPI process to ensure all team members understand critical requirements, timing and open issues. The stronger the planning tools, the less likely there will be non-value-added activity related to fixing issues the team failed to consider.
Benefits of this type of analysis and collaboration with the customer are minimized processing variation, elimination of defect opportunities, and mitigation of overproduction and over-transport risk.
Product acceptance/process validation. The production part approval process (PPAP) used for automotive and aerospace products is an excellent example of a process designed to ensure optimum communication during the product acceptance and process validation period. The automotive version, governed by the PPAP Manual published by Automotive Industry Action Group (AIAG), has detailed checklists which allow OEMs and suppliers to agree on the documentation and activities needed for each level of the process. While AS9100D drives a similar standardization in the aerospace industry, the checklists for aerospace PPAPs often vary by OEM.
Whether a PPAP is used or not, it is critical the EMS company provides detailed feedback on lessons learned during the qualification runs. This enables corrective actions to be applied before the product enters production. Unfortunately, there are cases where contract manufacturers simply adjust their processes to adapt to any issues related to a poorly designed product, material incompatibilities or component quality issues without communicating with the customer. Often these adaptations rely on manual processing or rework. The result of this lack of communication can be lower yields due to production process variation or significant quality problems if the work is transferred to another contract manufacturer.
Forecasting. One of the most significant benefits of Lean manufacturing philosophy is reduction in excess inventory. “Bonds” that define a minimum and maximum amount of material available from suppliers, and pull systems that bring material in as needed, require an accurate customer forecast. The EMS program manager is the key point in this process, analyzing customers’ forecasts against historical demand and other key factors. In SigmaTron’s model, this is further supported by a proprietary system that gives key suppliers, the customer and the EMS program team visibility in both material and project status.
Quality trends in the field. This area is frequently missing in the EMS-OEM communication loop. While customers want quality data from their EMS providers and do provide quality data on acceptance rate at their inspection points, they don’t always provide feedback on field issues. Field failure data can identify unanticipated design issues, component quality issues, failures in internal quality control procedures and continuous improvement opportunities. As the manufacturing expert, the EMS provider is often in a better position to interpret the data and recommend corrective actions than the OEM, particularly if the OEM relies heavily on the EMS provider to fill gaps in their engineering team.
Next-generation product design. While an OEM’s team often focuses on features and price points their product marketing team defines, an EMS provider looks at lessons learned in the prior product, component commonality and the optimum way to manufacture the desired feature enhancements. Collaboration in next-generation product design ensures the product reflects the best of both these worlds. Improved manufacturability, enhanced component commonality and efficient production flow reduce transactions, defects and concomitant costs.
Taking the time to develop communication checklists or adopt best industry practices helps ensure design improvements, forecast accuracy and optimized production processes are the rule rather than the exception. The earlier the communication, the more likely the customer will support the requested changes since the cost saving is likely to be greater.