The MOD Squad: Process automation at Dow

By Maggie Walker, Ed Sederlund, Jerry Gipson and Eric Cosman, Dow Chemical Co.

MORE THAN 30 years ago, the Dow Chemical Co. embarked on what ultimately evolved into a global corporate initiative: to develop and broadly leverage a standardized, highly integrated process automation system, incorporating basic process control, process information and safety-system functionality. Based on what we wanted to accomplish, and a lack of commercial offerings at that time, we developed several proprietary solutions, including a process control system that came to be known as MOD, which is short for “Manufacturing Operating Discipline.”

FOUNDED IN 1897 by Herbert H. Dow in Midland, Mich., the Dow Chemical Co. is a global leader in science and technology, providing innovative chemical, plastic and agricultural products and services to customers in 175 countries. From the very beginning, continuous improvement has been at the heart of the company, and forms the essence of its mission: “To constantly improve what is essential to human progress by mastering science and technology.” To achieve this, we’re committed to the principles of sustainable development. While it might sound lofty in some circles, this underlying philosophy has been an instrumental driver in our process control journey from the beginning.

The roots of our process automation philosophy go back to the 1960s, and are based on our operational strategy. Consistency and sustainability are key elements of that strategy. As a global company, it’s important to operate facilities in the same way, every time, to achieve consistently high quality, as well as process reliability and repeatability of best practices. We were striving for true “operational excellence” many years before it was coined by industry analysts.

Operational excellence includes safety performance, which was and is a key focus for Dow. We’re passionate about it. Protecting people, the community and the environment are non-negotiable priorities in our corporate culture. We must operate our plants safely and in the same way every time. Our "Vision of Zero" translates to zero incidents, injuries, illnesses, accidents and zero environmental harm. So our safety practices need to be repeatable and re-deployable as well.

We’re also driven to develop our own solutions by our engineering culture. We’re encouraged to look at problems and solutions differently. We ultimately integrate design, control and safety as a standardized system because we need solutions that improve the process. We design the solution around the process, not the process around the solution. Which element drives the development process is an important distinction here. You size the shoe to fit the foot. You don’t change the size of the foot to fit into the shoe. So, the needs of the process and our ingrained operating discipline are what ultimately create the solution. Our Manufacturing Operating Discipline (MOD) series process automation system was designed not by automation engineers, but by chemical engineers, who were intimately familiar with the intricacies of the process.

	FIGURE 1: OOOOH! SHINY!
	With enough iidot lights and pushbuttons to satisfy any primate, Dow's first attempts to automate were complex and wonderful.

This was the challenge, and we absolutely needed to accomplish all of it. However, in the beginning, commercially available process automation systems didn’t give us the capability that we needed. Technology was available that could be applied to the problem, and we developed several solutions based on general purpose computers and operating systems. Over time, we were able to develop a system that met our needs. In fact, Dow was the first company to certify a process control system with logical separation of the safety and automation functions in a common hardware platform. However, we didn’t exactly plan it that way. The driving force behind this was our passion for process safety, our operating discipline and the need to simplify the automation platform. We weren’t looking to invent something revolutionary. A confluence of process automation deficiencies in the market and the right people with the skills, needs and management support set the stage for Dow’s proprietary automation system.

In the late 1960s, all the plants we were familiar with operated with individual loop instrumentation, or even manually in older plants. Early efforts at automation were frustrating and cumbersome due to hardware incompatibilities and complexities. More time was spent dealing with keeping the control system running than was spent improving plant operations. This had to change. What was needed was a standardized, re-deployable process automation solution that supported our goals of overall consistency, productivity improvements, global operating discipline and innovation, all while maintaining high safety performance. The common thread throughout was our passion for process safety and this operating discipline.