In the first post of this blog series, we saw how operational complexities and market uncertainties drive electronics manufacturers to adopt a more modern MES platform. We also explored a few specific capabilities the solution must possess to meet the challenges which exist in executing operations. When evaluating an MES, manufacturers must consider whether the application can meet the functionality requirements, critical to success in Industry 4.0 and the modern marketplace characterized by uncertainty.

We established that the MES should provide master data management, with flexibility, proper context, and reuse of common elements. Planning should be simulation based and dynamic, considering all possible scenarios and priorities of the shop floor and supply chain. Material management should be efficient for the entire process, allowing both automation and operator driven operations to function effectively and with OS agnostic mobility for workers handling the material reels. BOM validation presents two extremely critical MES deliverables, first it should be integrated with the ERP to get the requisite BOM and then validate that each item was assembled in the right quantity at the target product.

Now, we move further and look at another set of critical capabilities the modern MES platform must possess.

Critical Capabilities Explained

WIP tracking

WIP management is a challenging task for manufacturers. While keeping WIP low can improve costs, line starvation impacts production time, so WIP inventory is a balancing act. With the fast pace of the shop floor, large inventory spends, material waste, material mismanagement and poor efficiency, effective WIP management requires frequent value-stream mapping.

The MES plays an important role in WIP management by aligning material supply with process demand and creating a pull system. Analytics within the MES play a role in determining the effectiveness of the process flow and reconfiguring it to ensure there is no inventory build-up. With advanced analytics it is possible to predict WIP issues and avoid shortages on the shopfloor. The MES must focus on the entire process when it comes to the WIP and not just on a single process, such as the SMT line. This process-to-process WIP management would mean control production execution across the entire operation.

Fig. 1 Example of a critical WIP operation

Figure 1 shows how analytics begins to identify critical WIP points. MES can track the status of each production order, including the location of each WIP item, the amount of time it has been in process, and the resources that have been applied to it. This information can be used to identify bottlenecks or other points in the process where WIP is accumulating or experiencing delays.

Equipment management and optimization

Equipment and tool utilization impacts output and profit. Complex equipment and both durable and consumable tools need attention to manage their health and ensure optimal utilization. Aligning staff, material, and maintenance with equipment, outside of production schedules is critical to run a profitable plant. When demand exceeds capacity, OEE optimization is essential, and this becomes complex with interdependencies going beyond the SMT line as more complex equipment populates the assembly process.

Fig. 2 Fig. 6 SEMI E10 equipment state models

An advanced MES provides a hierarchical resource model to track resource states defined by users or industry standards as illustrated in figure 2. The solution provides a rich set of transactions and includes calibration and verification of instruments aside from track changes in resource states, material, and durables. Native maintenance management within the MES tracks degradation and triggers maintenance automatically based on equipment usage and availability.

Equipment due for maintenance is unavailable within the system. An operator’s qualification and certification is tracked so only qualified personnel can access the resource. Further, the application tracks and record all maintenance activity and automatically requisitions consumables based on consumption during a maintenance cycle.


Data from the process is essential to improve quality and production efficiency and is required further down the supply chain for compliance and traceability purposes. The speed of execution increases the chances of something being missed during production and makes monitoring critical for electronics manufacturing.

Some indicators of a poor monitoring system include high reliance on manual reporting, low visibility across the process, data in disparate systems, rigid and paper-based reports, low alarms and alerts automation, no traceability of materials and process, and no integration with smart devices.

Fig. 3 Monitoring tool example for pick and place equipment

MES monitoring tools provides visibility across the entire manufacturing operations, as shown in Figure 3 for the placement process at an SMT Line. Real-time monitoring enables immediate action on automated alarms from the MES and allows analysis at the edge to reveal process changes and trends. Analysis provides intelligence, leading to improvements and optimization, integration with equipment while mobile device connectivity gives process owners the ability to act on intelligence any time from any location.


Electronics manufacturers are required to adhere to strict quality and safety standards and regulatory compliance, so, traceability is a mandatory tool to support them meet these requirements. However, managing traceability with multiple variants and complex production flows is challenging, especially, when data is being transferred and keyed in from disparate point systems. From material serial number down to reference designators, information throughout operations must come together, in order to effectively trace the history, application, or location of an electronic component or device through its life cycle.

Fig. 4 Process interlocking and traceability record

To ensure that all relevant information is available, it is important to have a system in place that tracks and record it in a centralized and automated manner. A modern MES can be used to automate the tracking and recording of information of each value-added step, covering all the operations from incoming material to the finished goods stage. Additionally, as shown in Figure 4, by interlocking process steps and enforcing process rules, MES can help ensure that traceability extends throughout the production process and that materials and components are processed in the correct order.

Defects and repair handling

The electronics market is highly competitive, and zero defects is the expectation for many manufacturers. As a result, they need to have in place an effective defect management system for repair and rework to save costs and meet customer expectations.

With the speed of change in product design and given how intricate electronics boards and assemblies are, quality issues are a day-to-day challenge. To prevent defective products from escaping to customers, electronics companies must address them where feasible and as early in the process as possible. At the same time, operator guidance must be robust and clear, to support operators in the rework process, step-by-step.

Fig. 5 Defect location with ECAD support

The right MES platform incorporates quality within the DNA of the assembly process and provides a plant-wide view of all defects through prep, printing, assembly, and beyond. Users can easily configure alternate routes for X-Outs and other defects, improving efficiency when working with less than 100% AQL. The MES adds repair guidance to work instructions providing all schematics, specs, and steps for the re-work and possible routes, considering existing and additional reverse workflows.

When repairing a defect on a multi-panel PCB, as shown in Figure 5, the system delivers the defect code, the board ID, the component part number, and the reference designator. The solution provides defect location on PCB ECAD and allows the display of key metrics like the first pass yield, defect rate per product, process, or supplier’s material on any device.

Next time we look at other critical capabilities, but most importantly how a modern MES can help improve NPI and engage people for a modern, agile and resilient Industry 4.0 electronics assembly process.

Read here Advanced MES Critical Capabilities for Electronics Manufacturing – Part 1.