Don’t fall short of the goal by missing the Three (3) Points-of-Integration
Engineer And Apprentice Using Automated Milling Machine
Machine Integration, Machine Monitoring, OEE Metrics, Paperless or “People-less” factory floor systems are names used to describe a technology that allows production (pieces/parts made) from machines to be passed with little or no operator or clerical intervention to the factory floor MES system. The hope is to improve timeliness of data capture, eliminate the cost associated with recording production data and improving the accuracy of the data captured. The marketplace today provides a path to successfully implement a totally automated factory floor system but it takes integration at three separate points. The hand-off of integration using internal staff, outside consultants/engineers or software solution providers can be determined for each level. It is best to fully understand these integration points since making the decision on where to apply your internal resources can make a big difference when it comes to making maintenance fixes and/or field upgrades. These three areas are listed below:
- The machines on the floor integrated to a PAC or PLC piece of equipment*
- The PAC/PLC integrated to a central computer like an OPC (Open Process Control) Server
- The integration of the OPC server to the MES factory floor system
Let’s take a closer look at each of these integration points. Number 1 (above) takes the knowledge of what “signals” need to be collected which, of course, needs to tie directly to the specific location on the machines that can be wired to a control unit. This requires a good understanding of the goals for the automation project. For example, if the project is collection of the OOE measurement of up/down time known as Availability of the asset(s) then only up and down time signal through I/O points on the machine need to be captured.
If however you want to evaluate the OEE measurement of Performance the actual rate of production verses the expected (or standard) rate. This will require automated capture of pieces/part produced from other additional I/O points on the machine. These signal can then be passed electronically to the MES system for job accounting purposes.
The OEE measurement of Quality, which is the capture of scrap pieces/part is usually manually entered unless it can be collected though some automation process (usually not present as an I/O point on the machine). And for each scrap recording there should be an associated entry of the reason from a predefined list of codes which most likely is manually entered too.
Regardless, the need to understand the integration points on each machine (#1) is usually best suited for your company’s internal engineering or maintenance department. That is because as time changes, requirements expand and new machines are added to your floor, the knowledge of the integration from these points to the PAC/PLC is best served from an in-house team.
The integration of the PAC/PLC devices to an OPC server (#2) is fairly straight forward and again should be owned and managed by an internal team. However, this might be a logical decision to outsource the wiring and OPC set-up to accelerate the implementation time and save internal resource effort. This service can be provided by many consulting and engineering companies that have this talent within their ranks.
Many times the last item (#3) above is forgotten or ignored when evaluating an automation project. But this is the only way to provide full analysis of the factory floor and give management the complete OEE picture in order improve and lean out the manufacturing process. The MES system contains in its data files the parts, process and job related data to complete the cycle of closed loop automation. Without the connectivity to the parts/process information (usually associated with a job) the capture of data from a machine will strictly be limited to the up/down time of the asset.
Without the integration to the MES data, you will only get one of the three OEE metrics…“Available.” And even at that, it might not include associated reason codes tied to the downtime occurrence which must be tied to a specific machine which is the most basic information needed to understand how to improve asset utilization. But understanding how to improve the availability of your machines is not process improvement which requires the capture of additional OEE measurements.
The other two OEE measures of “Performance” and “Quality” requires that the part and process information be brought into the mix and this information is found in the MES system. In addition, as mentioned above, “Quality” requires the capture of scrap which is often manually entered (along with a reason code) logged by the operator through the MES User Interface screen.
In summary, make sure you have internal discussion and a decision on the goal of your process improvement project. If direct machine data capture is to be part of this project then know the three points of integration. Discuss who within your company can provide the integration to the machines (#1) and potentially to a central server (#2). Integration to the MES (#3) should be provided by the MES solution provider.
*PACs (Programmable Automation Controller) coined by the market research firm ARC in 2001 is, in some research circles different from a PLC (Programmable Logic Controller). Check out www.opto22.com. However there has been no specific agreement as to what differentiates a PAC from a PLC. Some users feel the term PAC is simply marketing jargon to describe highly advanced PLCs, while others believe there is a definite distinction between a PLC and a PAC. In any case, defining exactly what constitutes a PAC isn’t as important as having users understand the types of applications for which each is best suited.
FACTIVITY’s Manufacturing Execution Software (MES) collects data from the factory floor and provides metrics needed to implement lean manufacturing practices. The system monitors equipment availability, performance and quality to visually display Overall Equipment Effectiveness (OEE) in real-time and integrates fully with your ERP.