One hears so much about Enterprise HMI and Manufacturing Execution Systems (MES) that it's easy to suppose these systems are everywhere. A visit to almost any manufacturing facility will show the contrary. A recent article in InTech magazine confirms this with a discussion about “the promise of tomorrow's systems” as having “a global view of all processes within the plant via the corporate intranet/ portal ...” Why is this a promise of tomorrow? Does the IT sector not have the tools and standards to accomplish this right now?
Let's get down to basics. Production orders need to go to the production floor and production results need to come back to management. The information flow should be instantaneous so that real time corrections can be made. Relevant historical information should be available to management at all times. When these mechanics are in place management can do its job. Without them, management is likely to be loose and error prone at the plant floor level.
The real question here is why, when the rest of the world is getting along with inexpensive and standardized IT tools, do plant floor islands of information still exist? The technology is there and the need is recognized. So why the disconnection?
Square Peg in a Round Hole
Most control system manufacturers have implemented and defended highly proprietary protocols in their controllers in an effort to lock-in end-users. This has been the game since controllers first hit the plant floor and the inevitable result has been high prices due to lack of competition. So it's not surprising HMI systems offered by these same vendors are priced an order of magnitude higher than comparable IT technologies. One thing that all HMI vendors seem to agree on is the pricing model and none dare violate it.
It's doubtful though that price alone would discourage broad deployment of Enterprise HMI systems since in a production environment the ROI should easily pay for the systems. But the more likely reason for lack of full adoption is that such systems are out of tune with mainstream technology. It is certainly evident that IT departments are resistant to deploying and maintaining these systems on their networks.
Two Different Worlds
The manufacturing sector is about five years behind where it should be when it comes to integrating enterprise to the plant floor. Nearly every other part of the manufacturing enterprise has been integrated with the latest technology and this has pushed right down almost to the plant floor where it stops short.
We have a picture where controls manufacturers seeking new profit opportunities have pressed up into the IT arena but their offerings aren't standard, are overly complex, are difficult to maintain and the pricing model unduly discourages full realization of what these systems could be . Conversely, IT departments and ERP vendors have tried to press down into the plant floor but this usually fails because plant floor control systems are highly specialized and aren't well understood. A lack of knowledge in this area can be a dangerous thing. A humorous example is when one IT department decided to “ping” all of the PLCs in a plant and automatically re-download non-responders. These are two different worlds and neither is likely to deliver a workable solution.
The Controls System Integrator is the Key
Today, with OPC standards and with inexpensive OPC servers for practically any control system available, the only thing preventing successful integration of control systems and enterprise systems is a lack of knowledge. The control system integrator is in the fortuitous position of already having controls knowledge (the most difficult part) and only needs to arm himself with IT knowledge. A controls system integrator will find this technology rather easy to master. He might be surprised at the support and assistance IT departments will extend to him now that he is dealing in “their technology.”
The controls system integrator is well poised to be the fence mender, the gap bridger and the builder of workable Enterprise HMI and MES systems for at least the next ten years.
This article was written and provided by Steven A. Hechtman, President of Calmetrics Company. Calmetrics is a control system integrator who specialize in efficiency issues and the development of simple, powerful, connected systems. They offer the following services:
- Design and programming of PLC control systems.
- Connecting PLCs to Powerful WebApps and databases.
- Producing clear and concise control system documentation.
- Emergency troubleshooting and support.
- Delivering PLC control and troubleshooting training.
- Advising on potential areas for efficiency improvement.