PCB + ASSEMBLY Digitally
PCB + ASSEMBLY Digitally connecting the entire operation Improving productivity with automated materials management In electronics manufacturing, the cost of materials can easily represent around 90 % of the cost of the product or 80 % of an EMS factory’s expenses. The most important costs that can be controlled are the investment cost of excess inventory, the cost of space needed to store the materials, and the cost of additional logistics operations required to manage and move materials. Lost production time is an additional cost caused by the lack of control of material inventory. An effective automated material management system can improve productivity in electronics manufacturing operations, while reducing scrap and rework issues. The core issue with today’s legacy materials management systems is that there is no single responsibility to manage all materials in the supply chain across the whole operation. Traditional enterprise resource planning (ERP) systems generally cannot track materials effectively once they are moved to the production area, causing inefficient planning and ultimately costing money. One of the key principles behind the innovation of Industry 4.0 is flexibility of planning, quickly adjusting production rates to meet changing demands from the customer. What is needed is a single point of management and accountability of all materials, no matter what they are or where they are, that is automated and digitally connected throughout the operation. First steps to improving material management Keeping track of inventory is a challenge in itself. Materials are received and stored in warehouses before allocation to production. Different materials may be stored in different warehouses depending on the type of material and the time it will be needed. Some materials that are located are on the shop floor to accommodate bulk delivery of a few high-use materials or to support an area of nonstandard self-contained production, such as for new product introductions and small lot sizes. The production area may include family setups, materials stored on feeders or on trolleys, and moisture-sensitive materials that need special handling, such as baking, and all of it needs to be accounted for in the overall inventory management system. Source: Siemens Business For inventory to be accurate, timely consumption information needs to be fed back to ERP so that the count of materials available recorded by ERP matches the physically available material. Only by keeping these records up to date can the orders and deliveries be on time and accurate. What about unmanaged, partly used materials that accumulate on the shop-floor once work-orders are completed? They also must be included in the inventory management system with accurate data on how much material remains on each reel so that they can be quickly and effectively re-allocated. In traditional manufacturing, ERP pushes materials to the shop-floor according to the master factory plan. The materials often are unmanaged and invisible in the supply-chain until a record of consumption is returned, calculated by counting the number of products made multiplied by quantities per product according to the original production bills of materials (BOM). Legacy factory operations can immediately save money and time by optimizing their control of materials using lean, just-in-time (JIT) Zusammenfassung Nachdem die Materialkosten in der Elektronikfertigung einen sehr hohen Anteil der Produktkosten ausmachen, wird durch Beispiele gezeigt, wie lohnenswert die Investition in ein neues Materialverwaltungssystem ist. Résumé Alors que les frais de matériaux représentent une part très importante du coût des produits dans le secteur de la production de composants électroniques, des exemples mettent en lumière l’intérêt d’investir dans un nouveau système de gestion des matériaux. Резюме Поскольку материальные затраты в значительной мере отражаются на стоимости электронной продукции, в статье приводятся примеры, показывающие, насколько выгодно инвестировать в новую систему управления материальными ресурсами. 46 EPP EUROPE April 2020
PCB + ASSEMBLY Optimizing material inventory will not only be cost effective, but it will also increase productivity as all information is known about materials in the process. Source: Business Siemens manufacturing practices. A lean “pull” signal can be derived directly from the machine operation, which means that kits of materials do not have to be prepared in advance; instead, all necessary materials remain in the warehouse ready for selection for immediate use on the machines and other processes. An automated pull system knows what the manufacturing process is currently producing, because it is linked to the bill of materials. Work-orders, derived from ERP, are managed at the machine level. In an automated, comprehensive, and digital material management system, work-orders are set up for each instance of production of a certain quantity of a product. The machine program, setup and execution data, and documentation are assigned at each step in each work-order. In this way, the exact routing of a work-order through multiple processes, each with their own execution instructions, can be known in real-time, including estimated start times, quantities, and run-times. The sequence of work-orders that will be executed can be viewed and tracked, which means the materials required for the current product in the current work-order are as well. With this, planning can be done accurately for changeovers that will take place for future products. Verification of materials during the logistics process can also be done during the setup of materials on the machines. An automated, digital management system prevents the machine or any other process from working until all of the materials have been correctly set up, according to the requirement defined in the work-order. Unique material IDs and their associated attributes are verified against the assigned setup that is derived from the work-order. This is far more comprehensive than simply checking the part number as done by many other solutions. For example, the MSD status is also checked, providing a warning and if necessary, preventing the machine execution, if contamination is likely to happen. This type of advanced verification process ensures that no mistakes in the materials setup are made, improving product quality performance while reducing scrap and re-work issues caused by incorrect material placement. The final essential piece of information required for automatic JIT delivery of materials to work is a live, networked interface tying together the machine processes, through which the progress of production, in terms of the number of PCBs produced, is communicated in real-time, along with the actual usage and spoilage of each of the materials. Material dashboards are used to better monitor and optimize inventory, while providing key metrics and guidelines. Source: Siemens Business EPP EUROPE April 2020 47
