Software Improves Productivity and Quality for NPI

Estimated reading time: 7 minutes

By Bruce Isbell, Valor Computerized Systems

There is no disputing the fact that electronics manufacturing is a tough business, especially for EMS/new product introduction (NPI) providers. NPI service providers face a formidable array of challenges to productivity and quality based on the sheer numbers of new product datasets that must be handled, evaluated, and converted into process instructions, compounded by the relentless onslaught of engineering change notices (ECNs), which must be responded to instantly. The dynamics of this kind of pressure can shake the operational infrastructure of even the best manufacturers to their core.

MACK Technologies Don Soracco works with mid-sized EMS company Mack Technologies, outside of Boston. They provide NPI design and manufacturing services for high-tech electronics markets that demand the highest levels of quality and reliability. Time is the life blood of all NPI operations, and Soracco uses software innovations to address time-to-market goals of his customers and improve the profitability of his company.BOM and ECNMack Technologies processes an average of five NPIs every week, with 5× as many ECN changes that must implemented. This amounts to about 100150 bills of materials (BOMs) that must be processed into their manufacturing resource planning (MRP) system every month. Prior to the implementation of new software, technicians spent an average of two hours per BOM for data handling, validation, and loading into MRP.

With the help of optimized process control software, Mack Tech reduced these two hours to about 10 min./BOM, for a saving of 230 work hours/month. That amounts to a direct savings of nearly 1.5 full-time workers, improved customer responsiveness, and a streamline effect that improves the entire process flow.

It is not just about saving time, but also improving quality. Soracco explains that, with the fast and accurate design for manufacture (DfM) analysis in Mack Tech's software controls, providing customers with a comprehensive DfM service no longer creates a bottleneck. Soracco notes, "About 90% of our customers are requesting DfM now, because we have shown the ability to offer objective analysis that actually improves NPI cycle time." This impacts overall product quality and process yield. With integrated DfM capability, "we don't have to wait until the pilot run to see if there will be any manufacturing issues," adds Sorraco. Figure 1 shows an example from Mack Tech where fast DfM saved a significant amount of time related to incorrect parts in the manufacturing BOM for locations U19 and U20.

Managing a high rate of ECNs is a constant challenge for any EMS company, and it is no different for Mack Tech. The biggest challenge with a high rate of ECNs is keeping a clear picture of their domino effect on the process. This was an emerging area of software capabilities that interested Soracco during beta testing of optimization tools. What EMS providers often lack in typical software solutions is a way to see the downstream impact of changing a location, part number, or reference designator, fiducial, etc., immediately. Mack Tech's software automatically and graphically indicates the impact of a BOM change (ECN) using red flags placed next to each element of the process definition, such as machine programs or documents that require an update due to the ECN. Soracco's team can execute the update by clicking flagged items; the necessary changes then propagate to all documents and programs, reducing time spent on changes.

The ECN impact visibility and resolution speed is possible because all data elements in both the product model and process model are interrelated and managed by the software's database engine. The data model is lean, due to the fact that "heavy" elements, such as CAD data, are not duplicated. Instead, one PCB design can be linked to many different BOMs to create assembly projects, and one project can be used in many process' setups for different machines or lines. Individual data items only have one instance, but many uses to keep the data model lean, linked, and fast.

Production DowntimeAnother critical area where Soracco and his process team created measurable improvement was in reduction of NPI cycle time on the shop floor. Mack Tech's SMT facilities, like most, constantly were battling line downtime for two major reasons: the need to debug component rotations or offsets and the need to debug incorrect or missing part data from the machine libraries on the floor. Typical average debug time for Mack Tech was 4 hours/NPI. This type of debug comes with a high cost, because the line is down while problems are corrected. Two software innovations allowed Sorraco's team to reduce 4 hours/NPI to 30 min. At an average run rate of five NPI per week, that equals line uptime improvement of 17.5 hours/week or nearly 76 hours/month. The result is almost two weekly shifts each month that an SMT line is producing product, where before it was idle so engineers could make corrections to the program or part data. These savings were achieved with advances in virtual sticky tape (VST) and auto generation (AG) of part data.

VST is a graphical process simulation that displays off-line all component rotations and positions using program and library-part data for a machine. With optimized process control software, the as-built rotations and placement locations are displayed in detail in the visual context of accurate component shapes placed on the CAD surface layers of copper, soldermask, and printing screen.

Before machine programs are generated, software neutralizes all rotations to one standard, regardless of which customer or design center created the PCB layout. With VST, NPI engineers spot all rotation and placement problems before building the first board. If any rotation is off, it is corrected prior to running the first article. In addition to rotation problems, other common issues such as X/Y offsets on asymmetrical components are corrected, saving time and improving quality through optimized placement location for each component.

AG also is put to good use by Mack Tech, quickly creating on-demand any missing part data from the machine libraries. AG creates machine-level library data automatically as needed during off-line process planning and programming. A library service passes the component dimensions, based on intelligent matching to the project BOM and approved vendor list (AVL), to the AG system. Software constructs a high-level universal or global shape; the AG algorithm then applies a detailed matrix of rules specifically for the qualified SMT machines in the process plan to automatically generate all required part data. The AG capability saves shop-floor debug as well as program-generation time. Using AG, Mack Tech reduced SMT machine programming time from an average of 8 to 12 hours/NPI. This creates a savings of 3035 hours/week in engineering labor. That is close to another month of work time that Soracco's engineers can apply to fine tune other parts of the process or to produce more NPI projects.

These library creation and management tools have also provided several other advantages to Mack Tech. Mack Tech has the capability to use programming resources in one plant to create run-ready machine programs for production in another plant. The software's extensive machine configuration, library management, and auto-generation tools make this kind of job portability and planning flexibility a routine matter. In fact, Mack Tech on a daily basis creates machine libraries and programs on-demand to get the best possible asset utilization from all their SMT lines, regardless of location.

With older products that would benefit from running on a different line, even without access to old CAD or BOM data, Mach Tech imports existing machine programs and re-outputs optimized programs and libraries for any line in any facility. This gives the company a competitive advantage and an upward bump in overall equipment effectiveness (OEE).

ConclusionMack Technologies benefitted from software innovation with automated BOM validation and upload into ERP; increased DfM coverage on incoming jobs to 90%, with DfM eliminated as a bottleneck cause; improved product quality and process yield with rotation neutralization and centroid correction; reduced time-to-market with VST and AG of part data. The EMS provider also was able to cut programming and documentation time with integrated ECN tools, linked data models, and auto generation of part data; create line-to-line and site-to-site job portability; and improve planning flexibility and OEE with centralized off-site programming.

In the Hollywood movie, "The Perfect Storm," the crew of the fishing boat the Andrea Gail were caught in the storm of the century, created by multiple simultaneous storm cells merging together over the outer banks of Nova Scotia. Process engineers don't have to go the movies to catch this action. They live it every day on the shop floor when ECNs, new rush orders, equipment downtime, material delays, and absenteeism all converge. Don Soracco found the answer to this "perfect storm" in optimized process control software. The dynamics of the EMS/NPI manufacturing environment make crisis inevitable, but with the right tools the negative impact of these events can be greatly minimized.

*Testing was performed for Valor's vPlan process control software.

Bruce Isbell is a senior strategic marketing manager at Valor Computerized Systems. Contact the company at www.valor.com. The article was written with input from Don Soracco, process engineering manager at Mack Technologies.