I recently sat down with an automation manager responsible for a subsection of a large manufacturing business. His company is embarking on an effort to standardize the use of process control narratives for all automation projects. To my surprise, the concept of process narratives was new to him. He didn't understand their purpose. But he was intrigued and asked many good questions I was happy to answer.
Have you ever thought about how many average families have been changed by having GPS devices in our cars? Just think back to the (not so) good ol’ pre-GPS days when you pretended you knew where you were going, only to find out you didn’t, and you never heard the end of it. When those wonderful gadgets came along, they put a stop to all the arguments about directions. Yet the change snuck up on us so quietly, it went mostly unnoticed.
Distillation columns are one of the most often used unit operations for separation and purification in the process industries. They can also be some of the most complex to operate and control, because they involve two-phase, multi-stage, counter-current mass and heat transfer (each tray or segment of packing is a theoretical equilibrium stage). The greater the number of trays, the longer the time constants related to composition changes.
ERP systems are supposed to be the “silver bullet” of computer systems. They’re supposed to solve just about every business problem you might have. They’re supposed to handle finance, purchasing, logistics, orders, shipping, inventory, manufacturing, maintenance and everything else with a beautifully integrated suite of modules.
And, you know what, except for the “silver bullet” part, ERP systems have actually delivered a lot of what they’ve promised. They really have done pretty well in finance and purchasing and logistics and several other areas. For most companies, ERP has been worth its weight in gold just by providing an integrated set of financial records and all the tools you need to manage the financial transactions of the company.
ERP doesn’t have that same track record when it comes to manufacturing, however. ERP doesn’t really support manufacturing that well and there are usually some extra pieces you need to bring to the mix to get ERP to really do what’s needed.
The real problem is that ERP just wasn’t designed to support manufacturing. When it comes to the actual manufacturing processes, or the quality processes, or even the material and inventory processes, ERP usually doesn’t do very well when it hits the shop floor.
You can tell this is the case by the number of Excel spreadsheets it takes to run the shop floor. And, yes, Excel is still the number-one manufacturing management software package in the world. Just look at the number of spreadsheets your manufacturing people use to run the floor. They probably have more spreadsheets now than before they had ERP.
So, what can you do? Can you help the plant without getting into a shop floor versus ERP war? Can you come up with something that helps the people on the shop floor? And, can whatever you come up with keep the ERP people happy and not make them the enemy?
Well, it’s not necessarily going to be easy, but there are some solutions out there that can help the shop floor people, and play nice with ERP as well. There are lots of different technologies, vendors, solutions, software, packages, platforms, toolkits and so on out there. Some of the best are even sold by the big ERP companies. I won’t use any of the names so I can protect the guilty (and the innocent). I’ll just call them manufacturing systems.
So, here’s what makes this all work. Manufacturing systems do more than just help the plant; they can make real impact on the bottom line. Manufacturing systems can help you reduce your costs, increase your quality, provide you with some new capabilities and even help you with your regulatory compliance issues.
So, how can manufacturing systems do this? Here are a few pretty random ideas on what manufacturing systems can do:
• Provide information and trends in real time
• Respond to problems on the shop floor
• Measure and monitor what’s going on
• Support better decision-making processes
• Capture information and its context
• Support continuous improvement initiatives
• Provide new quality tools like SPC / SQC
• Provide better specification management
• Support better asset utilization
• Provide more manufacturing flexibility and agility
• Increase productivity and throughput
• Increase yields and reduce waste
• Provide root cause analysis
• Support lean and six sigma initiatives
• Automate compliance processes
• Automate recordkeeping and reporting
So, why does all this work? Because these are the kinds of things they need on the shop floor. And, this is not typically what ERP is all about. If you can deliver solutions that do these kinds of things, they really shouldn’t conflict with the ERP system, and they can provide some major benefits to the people on the shop floor. And that can provide some major returns to the company, which isn’t a bad idea at all.
Quite often, automation projects become a plug-and-chug exercise in getting the code and HMI into the control system, according to the specifications, with little thought to the true purpose and strategy. This type of automation implementation can be successful, but does not protect your process from the dangers involved in making control system changes.
I applaud Dr. Skogestad’s real-world, practical approach to solving plant control problems in the latest edition of Control Magazine. In particular, his recognition of the importance of the control hierarchy and its relevance to how control solutions should be designed. It’s a refreshing change from the typical academician’s approach (matrix arithmetic, partial differential equations, Laplace transforms, i.e., boring and incomprehensible). I wish more university professors slanted their work this way. You’d see a lot more cooperation between industry and universities if that were the case.