How a novel approach can take time from 2 minutes to 2 seconds.
Poka-yoke is a Japanese term meaning mistake proofing. It was introduced by Shigeo Shingo as part of the Toyota Production System (TPS) and refers to simple fixes that address small variances in the manufacturing process.
Even production operations that focus on best practices in new product introduction (NPI) require poka-yokes. For example, SigmaTron International’s Tijuana, Mexico facility applies Advanced Product Quality Planning (APQP) and conducts failure mode and effects analysis (FMEA) to establish the most efficient, defect-free process. The facility utilizes a product part approval process (PPAP) for automotive projects to validate the process, while customer-specific validation processes apply to projects in other industries. Once production begins, the team monitors processes and tracks defects using statistical process control (SPC) and other forms of quality data collection. When defects occur, the team schedules a kaizen event, employing tools such as 8D problem solving, Six Sigma’s define-measure-analyze-improve-control (DMAIC) and poka-yoke to analyze and correct the root cause.
Using Lean Six Sigma to prioritize projects, optimize capex, and inform employee recognition.
Lean Six Sigma is a powerful tool for production teams committed to continuous improvement. Viewed as individual activities, however, the overall impact of the improvements it drives may not be obvious. The Continuous Improvement teams in SigmaTron International’s Tijuana, Mexico, facility address this with an annual review meeting that looks both at accomplishments over the past year and year-over-year trends. The top three teams are recognized for their accomplishments.
Respinning a board to eliminate PTH parts can pay off in production.
When an electronics manufacturing services (EMS) provider is involved in developing a new product, it is easy to provide design for excellence (DfX) recommendations that align with Lean manufacturing philosophy.
Addressing manufacturability or testability issues associated with legacy products is much more challenging, however. The reasons printed circuit board layout or product design choices may not be optimal are many. Design cycles have been compressed and design resources have been cut at many OEMs. When layout or product development is outsourced to a third-party design team without manufacturing familiarity, the result may be a PCB assembly (PCBA) that meets form, fit, function and cost recommendations, but ignores industry standard design rules, sole sources much of the bill of materials (BoM) or requires unnecessary processing.
SigmaTron’s new product introduction (NPI) process evaluates these issues as new projects are onboarded through a combination of an engineering team review and automated checks through a third-party design tool. When improvement opportunities are identified, the team can provide redesign or PCB layout services to correct the issues.
Do multiple single-spray-nozzle conformal coaters outperform a three-nozzle machine for volume builds?
Electronics manufacturing services (EMS) providers often have to evaluate equipment selection tradeoffs on more stringent standards than original equipment manufacturers due to their needs for flexible capacity across multiple clients.
How does AI contribute to continuous improvement?
Depending on whom you talk to, artificial intelligence (AI) is likely to open amazing possibilities or lead to the end of humanity as we know it. The reality is that when appropriately used, AI eliminates a lot of repetitive tasks that have high levels of variation and cost when done manually. In the quality realm, this opens the door to a discussion about whether a truly automated inspection process is a non-value-added or necessary non-value-added activity.
Manual inspection is costly, and accuracy can vary widely among operators, the time of day the activity is performed, or even the day of the week the activity is performed. Quality philosophy has long held that it is better to prevent defect opportunities (quality assurance) than to try to inspect them out (quality control). If a printed circuit board assembly (PCBA) can be 100% visually inspected by machines during SMT and secondary assembly processes without significant throughput time, however, does it make sense to do so? Let’s look at the pros and cons:
Non-value activities are sometimes unavoidable.
One challenge for electronics manufacturing services (EMS) providers implementing Lean manufacturing practices can be customer buy-in. While an original equipment manufacturer (OEM) can design a process with minimal non-value-added activity, customer requirements may revive some necessary non-value-added activity and it is up to the EMS provider to find a compromise that satisfies the customer requirements while minimizing the cost of resources associated with the non-value activity.
A recent example of this occurred in SigmaTron International’s Chihuahua, Mexico, facility. A consumer product customer added conformal coating to a product experiencing field failures related to operating environment issues. An automated selective coating machine is used that controls conformal coating deposition areas and application thickness. The customer wanted an automated visual inspection step added to ensure any overspray or missed coating was caught.