As explained in ARC Advisory Group’s updated Collaborative Process Automation Systems (CPAS) study, process historians provide key functionality within ARC’s overall CPAS vision. Although it appeared that process historians—along with process automation systems in general—have had a period of slow progress, we’re now seeing specific activity that provides a strong indication that process historian suppliers are moving in what ARC believes is the right direction. In fact, a handful are getting very close to becoming the object-based, enterprise-wide, operations-center-like, process historian described in the “CPAS 2.0” study.

Historically, process data historians have been the plant manager’s favorite tool for understanding how the plant is performing. Initially, data-driven time series tabular displays and trends were sufficient. However today, many users at both the individual plant level and across the enterprise want to be able to collaborate and project their understanding based on a single version of the truth. They want to be able to harvest any relevant information assets without boundaries in real time and work collaboratively with business counterparts and colleagues at their sites and in other plants using a comprehensive, state-of-the-art toolset and a common understanding.

With the last generation of process automation systems, a common theme was “he who owns the data wins.” This limited potential performance. Instead, everyone with a need to know should have access to the data. The theme for today’s system should be, “everyone should own the data.”  But incremental performance is a function of how individuals deal with the unknown or misunderstood data.

Trends and challenges
Historically, process manufacturing plants have been operated so that steady-state operations are maintained in the face of multiple disturbances and rate or grade changes. Although some facilities still operate in this mode, the next-generation plant does not.

The economics of steady-state operations are being replaced with a dynamic economic environment in which adapting to changing supply streams, creating multiple products and frequent transitions from product-to-product or grade-to-grade are the norm. Tighter quality specifications and the need to maintain minimum inventories, plus more stringent process safety measures, cyber security standards, and environmental regulations further constrain this dynamic environment.

Many plant managers use their historians to understand what has happened, their intellect and experience to understand what is happening, and an educated guess as to what will happen. Relative to risk management, this is not acceptable. Plant managers need tools that define precisely what is happening, what will happen, and if the current trajectory is leading to an unacceptable result, what needs to change to achieve an acceptable result, thus providing the opportunity to take corrective action.

In a well-controlled process plant, shift operators will experience no emergencies or crisis 95 percent of the time. But havoc and uncertainty can prevail during the remaining 5 percent. This 5 percent (and perhaps the 10 percent preceding the havoc) represents the opportunity cost in not having a better understanding of manufacturing and work processes.

This doesn’t bode well for the future, since the major factors limiting these losses are experience and good judgment. The big difference between your current “best operator” and the next operator that will replace him or her, is experience and judgment.

Today, we see the CPAS historian as a station on a message bus adding value to peer applications. This enables advanced, high-availability computing and the associated benefits. The CPAS historian broadens the concept of a “single version of the truth” from the plant to the enterprise. This facilitates a broader range of collaboration and precision. The solution also provides an excellent platform for business intelligence and appears to be evolving into a platform to enable true operations center functionality for a plant or set of plants.

Dave Woll , dwoll@arcweb.com, is vice president, ARC Advisory Group, Dedham, Mass.

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