Look before You Leap: Implementing Successful OPC Projects

Jan. 17, 2008
The Right Way to Implement Industrial Automation Connectivity

By Eric Murphy, ControlGlobal.com Columnist

The vision for OPC from the end-user’s perspective is to be truly plug-and-play. Much like most people know little of the underlying protocol details of USB or Ethernet, they can still buy products and quickly assemble networks. Yet it is important to remember most companies are purchasing their components from trusted vendors, and have IT professionals who are responsible for planning their business infrastructure. Why would implementing industrial automation connectivity be any different?

“The Way We See the Problem is the Problem” – Stephen R. Covey

Setting up a simple OPC client-server connection is plug-and-play. The standards have paved the way for interoperability between countless devices, applications and software packages.  In fact there are many live demos available on the web that let even a novice OPC user, get connected and reading data in minutes.  This ease of use, along with the other benefits OPC brings to the table has made OPC the connectivity standard of choice. That doesn’t mean every OPC installation has been trouble free. A survey conducted by ARC in 2006, asked end users the level of problems they experienced with OPC. While the majority reported no or minor issues, there were still a significant number that said they had some or many major issues. Experience shows these major issues commonly stem from two main sources:  product quality and improper system design.

“It's not a Blame Game. It's Accountability! It's Accountability!” – Terry Moran, Nightline

Initiatives like the OPC Certification Program are helping vendors to build better quality, certified products.   Compliance testing assures users that products meet the requirements of the OPC specifications.  Interoperability testing extends basic compliance to multi-vendor functionality testing in a clinical setting. Vendors have to take responsibility to ensure that their products meet these requirements as a minimum. Committed OPC vendors go further; take ownership of interoperability, and partner to ensure their products will work together in complex industrial settings.

Vendor accountability is also key to project success, particularly with complex OPC architectures. The OPC software vendors must take ownership for the success of the project before it goes live. This means they should be involved in all aspects of the OPC architecture and design. Accountability means more than simply being at the table. Every project has several constituents, and the interplay between these constituents affect the overall project success. Ownership of the project means working to solve issues, regardless of where the problem lies and not just pointing fingers.

"If You Can Dream it, You Can Do It.” - Walt Disney

OPC interfaces are readily available for many systems, and when using OPC Certified products, they should connect and communicate with little trouble. However, since OPC solves the issues of proprietary interfacing, it is all too easy for implementers to think: ‘We don’t need to spend time or money on system integration, we’ll just use OPC’. Although OPC solves the big interface question, there are still implementation factors to consider. The plug and play nature of OPC products allows for very powerful communication systems to be built. The issues associated with such functionality must be planned for and addressed: multiple data paths, data through-put, guaranteed data delivery and redundancy, network interoperability, communication disruption and recovery, maintainability and geographically disperse systems.

“Plans are Nothing, Planning is Everything.” - Dwight D. Eisenhower

Regardless of what technology is being used, users need to be working with a trusted vendor who understands the requirements and has the products and services to meet their needs. OPC has done amazing things with leveling the playing field for system interoperability. However, no protocol, technology or product can remove the planning and understanding needed in creating industrial strength connections between different systems.

“The Way We See the Problem is the Problem” – Stephen R. Covey

There is risk inherent in any project. Reducing this risk in OPC projects involves both risk identification and continuous risk management. More often than not OPC is not the issue. It is ignorance of OPC risk that is the root cause of many problems. For plug and play components to be successful in an overall system, there must be proper planning.

The first step of planning is identification of possible issues before they become problems. Next step is to analyze the data, and convert risks into decision making information. Proper planning converts risk information into decisions and actions. Implementation is not just deploying software. It is prioritizing actions, monitoring risk mitigation tactics and making necessary corrections when reality deviates from the planned risks. And finally good communication of the process to all constituents is fundamental to the success of any project.

“Risk Comes from Not Knowing What You’re Doing” – Warren Buffet

For a successful project, the right people need to be involved in all aspects of the process; from design and analysis, through factory and site testing, to deployment and monitoring. To reduce risk in complex OPC projects requires specialized training and the involvement of the people with the right qualifications. No one would expect any other technology to run a plant for years without proper planning and testing. Using plug-and-play OPC is no different.