When considering how to fully access the value that MES (manufacturing execution system) technology brings, it's important to understand that its really about identifying and filling the gaps and voids between operations and your ERP system. The ERP directs macro-scheduling and a wide variety of activities on the plant floor such as asset use, production balancing and crew/operator planning. By using MES as the integration path to tie the ERP to the process control layer, you expose information and the status of individual assets in the plant.
Positioned as the bridge to process control integration, MES provides insight into how well you're running (performance), what it is that you're running (operations) and how much you’ve made that is salable (quality). These are valuable insights and warrant a deeper understanding.
Performance
Manufacturing plants have a lot of data about how much/how many things they make. The problem is that the data they have lacks the context of the type of product made and the issues experienced while producing it. MES performance (aka OEE—overall equipment effectiveness) provides the required connective contextual information to give plant leadership the ability to see what they made from a productivity perspective against a standard of measure.
One path to standardized OEE calculations is to add MES performance to a few select assets on the line to gain an understanding of how the entire line is running. Based on that information and resultant actions, further justification is often provided to add more details and additional assets to the model, thereby evolving the use of MES over time.
With OEE information and associated downtime causes known, it is possible to understand where it is most feasible to improve manufacturing lines build an ROI (return on investment) for a project that will make an area of the plant more efficient and more profitable.
Quality
Manufacturing plants determine quality by performing a significant number of checks throughout the production process. Many of these checks are performed on paper via tally and clip boards. The majority of the checks are required on a very frequent basis (e.g., every 15 minutes or every hour), making it a very labor intensive process. Asa result, this manual process of checking is prone to human error.
One way to close this gap is to implement MES quality. MES quality provides an electronic means to enter and integrate quality measurement directly into SCADA clients or operations visualization tablets. The use of MES provides a means to ensure quality checks are performed in a timely manner and are accurate regardless of the measurement mechanism. The resulting reports, alerts and insights show how well systems are running within the expected quality parameters. This information can be used to implement a positive product release approach with a high degree of confidence.
Operations
When you relate information from one function (OEE) to another (quality), it unlocks even more insights. For example, production scheduling is a challenging area of plant operations. Traditionally every facility has scheduling algorithms embedded in a large Excel file developed through years of measurement, assumptions and tribal knowledge.
The catch is, there is typically a very limited number of people in a plant who truly understand the complexity of the operations and how to use the spreadsheet. These schedulers spend significant time to build the day’s changeover matrix via a manual process for the plant. As a result, these systems are reliant on those one or two people who can, as humans, be prone to error based on misapplied assumptions and mistargeted tribal knowledge.
MES for operations takes the MES quality and performance data, compares past performance and results, and recommends scheduling configurations that optimize changeover, cleaning and set up requirements on a product-by-product basis. Operations MES can provide the ability to set ingredient orders based on inventory and auto-schedule the inventory based on the equipment that's available today, allowing operators to focus on more pressing human element issues and coordination between departments.
Closing the operations-to-ERP gap
Looking at MES technology holistically, its functions and value rollup into the three large buckets of performance, quality and operations. Manufacturing plants have solutions to address the individual demands of these buckets. The challenge is that the solutions are typically siloed. The data is siloed. The information and the flow of it is siloed. The people who use the solutions live inside the solution, sometimes as rudimentary as an Excel spreadsheet. They print out information and they give it to the operators daily. The printout has no intelligence around or in it. There's no information about how well a plant is at attaining the goals set for it. To understand that, plant resources need to go back and retroactively dig through all the hard copy data.
MES provides the ability to see all of that in real time and influence the outcome by communicating its results to the ERP system. Rather than having dead end data silos, MES provides data context, access and understanding to empower operators and plant leadership with the tools to deliver results and improve upon them daily.
Bruce Slusser is digital transformation practice director at Actemium Avanceon, a certified member of the Control System Integrators Association (CSIA). For more information about Avanceon, visit its profile on the CSIA Industrial Automation Exchange.
