BMS or PLC? Controlling the Regulated Environment

Sep 01, 2004
Volume 17, Issue 9

Jeff Bredeson
In the ever-changing world of pharmaceutical facilities delivery, there appears to be a growing interest in the utilization of programmable logic controller (PLC) technology and process systems to control HVAC applications.

Background InformationUntil recently, HVAC equipment and building management systems (BMS) were thought of primarily as non-impact or indirect impact systems to most regulated facility owners. The last decade or so has truly marked the evolution of quality management in the life sciences industry. Companies, as well as the various regulatory agencies (FDA, HPB, MCA, etc.), have realized that there is a direct link between the temperature, humidity, pressure, or particulate count in a space and the quality of the product being manufactured, studied, manipulated, or stored in that space. The logic is that an excursion of these variables caused by a malfunction of the system controlling these points of data — the BMS system — has "direct impact" on product quality, and, therefore, these systems should be qualified and must pass regulatory muster. As companies are starting to embrace a risk-based approach to validation and to assess systems and component criticality, they are finding the environment is an important part of the quality equation in a regulated facility.

Now that the criticality of these systems is recognized, the discussion turns to finding the right control solutions for regulated environments. Historically, commercial BMS systems, the same systems used in schools, office buildings, and hospitals, were utilized in critical industrial areas. Today, many BMS manufacturers are improving, hardening, and securing these systems to make them more industrial in appearance and operation. At the same time, some owners of regulated facilities are looking at other ways to meet their needs. One of the solutions being explored and tested is applying programmable logic controller (PLC) technology to HVAC applications. This article identifies and compares the advantages of each approach from a pragmatic perspective.

Before the advantages of each system are individually addressed, let's examine the critical issues more closely from the building owner's perspective.

Companies now view facility automation systems and component criticality as part of the quality equation.
Risk Mitigation and ComplianceRisk mitigation and compliance are critical because the penalty for non-compliance is so great, as many companies are learning. The ability to procure robust technology that enables the attainment and maintenance of compliance is not just "nice to have;" rather, it is the proverbial "ticket to the dance." Companies must have a product that can be applied with compliance in mind and meet the relevant regulations — Title 21 CFR Part 210, 211, 820, and 58, as well as Title 21 CFR Part 11. From a system purchaser's perspective, there are several considerations. First, is the vendor's solution compliant? Further, is the validation process in line with company standards and procedures? Is there precedence of the solution being validated? Finally, is the cost of compliance within reason?

Many system providers claim that their products are compliant with FDA regulations. In reality, when it comes to systems that include hardware and software, compliance must be built into the product to assure the result. There are very few off-the-shelf systems that are compliant out of the box. In fact, compliance always includes some level of procedural action on the part of the owner. This fact stresses the need to work with a solution provider (PLC or BMS) that understands the regulations that apply to their area of the facility and can provide references of successfully validated solutions. If you are asking a solution provider to apply a technology to an area of the facility that is not their core competency, then you are asking for an unpredictable outcome.

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