A modern MES is widely considered the foundational technology for Industry 4.0 in manufacturing. Having an MES in place that delivers specific improvement for a complex and intricate manufacturing operation can be critical to success in an increasingly uncertain marketplace. Electronics manufacturers have highly complex processes, large supply chains, and an increasing product mix, that needs to be brought to market quickly. A single electronic product may have thousands of components and may require multiple complex processes across a variety of sophisticated equipment and machines.

Electronics manufacturers also grapple with the burden of increased customization within their already complex product mix with short product lifecycles. The supply chain, especially semiconductor chip supply, remains uncertain and there is added pressure for zero defect production. Simply meeting these challenges and staying afloat is a challenge, but companies need to deliver higher profits and increase shareholder value. To do this, electronics manufacturers turn to Industry 4.0 technologies and MES specifically.

An MES that works for the industry needs to check every box when it comes to managing complex workflows and controlling processes. In this three-part series we will explore what an ideal MES for the electronics industry looks like and focus on the critical capabilities the solution must have to help electronics manufacturers address the challenges they face.

Critical Capabilities Explained

Master Data Management

According to Gartner, “Master data is the consistent and uniform set of identifiers and extended attributes that describes the core entities of the enterprise….”

For electronics manufacturers, these core entities include BOMs, CAD, ECAD and EDA files, routes and recipes, tools, materials, and processes. The main challenge is the easy revision of these master data elements while ensuring change control is enforced to revisions and new versions following a clear and well-defined approval process. A common issue is having execution relevant master data elements reside on other enterprise software like the PLM or the ERP. 

Fig. 1 Repeated re-usable sub-flows

The MES plays a critical role in master data management by providing the required level of change control through versioning and allows certain master data elements to be reused. Figure 1 illustrates how the MES allows reuse of certain sub-flows in the PCB assembly process, allowing changes in BOMs and recipes while maintaining the correct version of the given workflow. 

Since master data elements might reside in different applications, integration with the PLM or the ERP ensures that the MES provides a reduction in effort, time, and errors by allowing reusability.


The translation of specs from the ERP into a concrete schedule with clearly demarcated timelines is the core element of planning. Planning becomes challenging with a larger number of variants, smaller lot sizes and increased customization. The added pressure of shorter lead times means that electronics manufacturers rely heavily on planners to create schedules that can be relied upon and can cope with market uncertainties and demand fluctuations.

Fig. 2 Planning synchronization flow

The modern MES addresses these challenges by automating planning and making it fast by allocating and clustering product families across, SMT, THT, and packing. Simulations reflecting short-term restrictions and interruptions provide a reliable schedule with minimal variance. Figure 2 reflects how planning can be adaptive and accommodate changes based on urgency and/or material availability. Flexibility and automation applied across multiple assembly lines translates to better results.

Material Management

Material-related line stoppages is a major concern in SMT plants. Certain materials such as MSD components and solder paste have a specified shelf-life/floor-life and require proper temperature or humidity settings. Other materials must be used within a specified timeframe after opening the package. On-time and precise replenishment of the material reels on the pick-and-place machines and correct handling instructions with time-bound execution directives is crucial.

Fig. 3 Example of an automated material replenishment workflow

The MES managing the process should have all details for every component and their handling requirements on the shopfloor. The solution should be able to request, move and assign materials between locations as shown in Figure 3. Ensuring complete traceability of material through WIP and utilizing time or moisture-sensitive material properly is the core feature of the material management module.

Timely inventory replenishment is an essential deliverable for the MES. Ensuring automated and well-orchestrated material flow through the SMT line and the entire process is important, a modern MES integrates with and controls storage towers and AIVs to ensure maximum up-time across multiple lines.

Recipe management

A recipe is a crucial component of the electronics assembly process. It contains all parameters relevant to assembly and the placement equipment contains a placement list and component set-up. Complex recipes involve special recipe editors and SDKs. The challenge is ensuring that each recipe remains unchanged while being used yet allowing recipe components to be reused based on parameters involved. Using the right recipe version and gathering data of the recipe instance used as evidence is critical to the overall process.

Fig. 4 Recipe definitions and recipe instances

The modern MES platform addresses challenges of recipe management by providing a centralized RMS and equipment integration that allows for direct upload and download of the required recipe. The MES provides a context resolution mechanism to ensure the right instance is executed on the correct equipment for a given lot or PCB, as shown in Figure 4.

The MES enforces the applicable recipe automatically through equipment integration and ascertain that the recipe hasn’t been modified. This goes back to version control and reusability through a verified internal configuration within the application. Highly automated production environments with AIVs, mobile storage towers, and automatic pick-and-place equipment demand extremely precise recipe management and a modern MES has this advanced capability to support the process.

BOM validation

BOMs can be complex, as can the recipes, materials, and equipment. Errors may occur when programming a pick and place machine. For example, if an engineer bypasses a component that should be part of the placement list or a wrong part number for a given reference designator is programmed.. BOM validation ensures each product BOM matches to the pick and place recipe preventing errors to appear on each side of the PCB assembly reducing wasted time, effort, materials and consequently scrap and rework rates 

Additionally, the increased use of LEDs, introduces other challenges in BOM handling. The potential for defects appears when the brightness index number (BIN) from one reel to the next are not compatible and the traditional methods for component traceability and line setup are not sufficient to support and assure the valid LED pairing.

Fig. 5 PCB BOM validation sequence

As illustrated in figure 5 the MES validates the BOM each time a product is about to be processed. The system ensures the interlocking between product, BOM, process step, machine and recipe at the right time for processing.

For all the equipment at a line or standalone operation that should consume BOM items, before production takes place MES ensures consumables are present in the right quantities and in the right place, such as the proper and valid solder paste at a printing machine. After a PCB gets processed the MES cross-checks and verifies that each BOM component has been placed on the board. Only with this automated validation can the production move along smoothly and at higher speed.

For more critical MES capabilities for electronics manufacturing, stay tuned!