By Nels Tyring, Chairman, TVC Systems
IT ALL started in the early 1970s with the debut of the programmable logic controller (PLC), which allowed discrete manufacturing and smaller process plants to enjoy the benefits of automatic control. Before this time, the automatic control market was the province of large process plants and manufacturers of direct-digital and then distributed-control systems. The PLC and the advent of the microprocessor a few years later changed the game. Since applications for PLCs tended to be below the horizon of the large controls manufacturers, and since a good deal of specialized knowledge was required to apply them, a new kind of third-party implementation was required, and a new industry sprang up. These firms came to be called control system integrators (CSIs).
These CSIs multiplied rapidly, and by the late 1980s, there were more than 2,500 in the U.S. alone. Since there was no accepted definition of what a CSI should look like, what they should do, what methodology they should use, or how they should run their businesses, it was an easy-to-enter and easier-to-go-broke-in business. Firms came and went in rapid succession, leaving a lot of their customers with less-than-satisfactory systems, little or no documentation, and sometimes a total lack of support.
Defining the Job
In 1994, a group of well-established and successful CSIs formed the Control and Information System Integrators Association
(CSIA), and first set out to define CSIs and their essential parts. This resulted in the Best Practices and Benchmarks Manual
in 1997, and gave CSIs yardsticks to successfully implement systems and operate their businesses. The manual covered not only technical areas of producing successful, finished projects, but also the business operating practices that assure success and continuance. Potential users of CSI services now had an objective way to evaluate integrators’ technical and business practices, which could help their projects succeed. They also could gauge a CSI’s potential for providing long-term support for their project.
Three years later, CSIA established its CSI Certification Program, which are based on its best practices and benchmarks, and warranted by a third-party auditor. There are now more than 80 CSIA-Certified Control and Information Systems Integrators worldwide, and this number is growing by more than 25% per year.
Enter the Integrator
Having defined the control and information systems integrator and established standards enabling certification, we’re now facing the fact that CSIs are frequently placed where they can do the least good in the construction process. Conventionally, the CSI is considered a part of the building trades, though, in reality, there is a lot of difference in their skills, roles, and place in a project.
Just as the process engineer must define his process at the beginning of the design sequence, controls engineers must define the strategy, sequence of control communications between major equipment modules, and the overall orchestration of the automatic control of the process. They must also interface process controls to the operators, engineers, managers, accountants, and various government agencies seeking to regulate the industry.
The conventional engineering process traditionally defines the project’s materials, methods and tasks in great detail, and issues plans and specifications for construction. These detailed documents are then bid for best value by the various trades. Government-certified journeymen and master tradesmen then execute the actual construction using these documents. Engineering plays a small part in the roles of the building trades because that’s the responsibility of the engineer of record.
Sometimes Too Little, Too Late
The role of the control and information system integrator is substantially different. The bid package for controls normally contains a specification outlining customer-preferred components and their manufacturers, a process and instrumentation diagram (P&ID), a set of process operating parameters, usually in the form of ISA Instrument Data Sheets showing pressures, temperatures and allowable or desired increases or reductions in systems operating parameters, and a control points list. From these beginnings, the control engineer engineers, designs, and builds a system that will automatically perform precise, accurate, automatic process control.
The construction documents are given to the low controls bidder when the contract is awarded. This is long after many critical decisions, from the controls engineer’s standpoint, have been made about major and sometimes minor pieces of process equipment. These components increasingly have their own onboard intelligence, which also must interface with the overall plant-control system. To make matters worse, the owner frequently seeks to save money by buying the control system’s field elements before the control engineer arrives on the scene. Details of these field devices often aren’t disclosed until they’re installed, and the attempt to interface them with the control system is underway, and their appropriateness for use or connectabilty is in question.