Are You Using A Sledgehammer to Monitor Temperature and Humidity?

Facilities often use complex and time-consuming tools to accomplish what should be a simple task.

By Jon Aldous, Life Science Product Manager, Vaisala

The requirement to monitor a chamber, room or warehouse for temperature and humidity at first sounds quite straightforward.  Items required are easy to list: first, you need a system that will accurately record the conditions that your product resides in—check. Then, you need a system that will alert you if those conditions exceed your tolerances—check. Finally, you need a system that can create reports based on the conditions and any alarms that have occurred—check. A quick web search reveals that there are many monitoring systems that will satisfy your checklist, but I’ve seen facilities use complex and time-consuming tools to accomplish what should be a simple task. A sledgehammer can get the job done, but not if the job is opening a walnut.

Chart Recorders: Simple & Small-Scale
The simplest system is a chart recorder.  Installation is straightforward: 1 per location. Conditions are recorded on a moving chart with pens to produce a historical trail of the monitored conditions. You can also configure chart recorders to provide local alarming. To some, chart recorders are the best thing since sliced bread! Simple installation, little or no validation requirements, and best of all – if it breaks, you can replace it with another inexpensive recorder. These are easy to recommend to anyone who monitors 3 or 4 chambers; they are simple, inexpensive and easy to maintain.

Life gets a little more complicated when your monitoring requirements scale upwards. What if you need to monitor 50 locations? If you stick with chart recorders, it’s going to get expensive. The amount of time changing charts each week alone has you spending one day a week collecting and storing records.  What if you find out-of-tolerance readings? It’s likely you’ll spend another whole day investigating each chart, initialing each excursion, and writing deviation reports. Maybe it’s time to go computerized…

Customized BMS & SCADA: Sledgehammer v. Walnut
However, what used to be a simple choice is now getting more complex. Should you use a bespoke software package that is designed just for you? Should you use your existing building management system to monitor? (After all, isn’t that what it’s designed to do?)  Or do you go for the off-the-shelf package, which is simple and may have limited function?

Now we run into other issues; when we deal with computerized systems, we also have to involve validation departments and be aware of federal guidelines such as 21CFR Part 11. The use of a computerized system requires that electronic records and signatures be considered. To make it even more complex, you need to be thinking of external audits and GAMP classifications. Companies who design software need to follow coding rules and allow customers to audit their processes (either in person or by questionnaire).  The level of software that is being provided is typically classified by the GAMP forum as being of 1 of 5 levels. Level 1 can be a widely distributed software such as Microsoft Windows and Level 5 could be a completely custom-designed system, created and coded just for you.  In addition, the higher the GAMP classification level, the more complex the auditing and validation design.

Remember back when you only monitored a few areas with a chart recorder? No software, electronic records or signatures, and therefore, no 21 CFR part 11 requirements. Life was easy!  But with greater monitoring needs, what are your best choices?  How do you determine the level of effort you need to expend validating the installation and verification of a new monitoring system?

You could use the Building Management System (BMS) that your facility already has. This provides the flexibility to add monitoring, but there are some downsides. First, can you easily validate any change on such a large, bespoke system? Would this be a simple or complex change control? Second, how would you manage day-to-day alarms, reporting, and control? What if you need to manage those items (or assign management) by personnel who are assigned discrete areas of responsibility? Typically a BMS runs the plant because they are designed to control and allow engineering personnel to efficiently generate environmental conditions specific to a product or process. In light of these issues, using a BMS to monitor conditions is like using a sledgehammer to crack a walnut. It can be done, but it’s neither simple nor advisable.

One step away from the BMS is a Supervisory Control and Data Acquisition system (SCADA), although they can be one of the same. It’s possible to use SCADA-based software to design a simple monitoring system; this is sort of like programming your Excel sheet macros with VBA code. The platform is standard, but there’s a great deal of custom programming to give you all the functionality you’ll ever want.  Just be prepared to get your auditor’s hat on and check the code standards.  This should be followed up with a validation documentation package that reflects a GAMP level 5 design. Again, this might be too much system for basic monitoring requirements.

Off-the-shelf Monitoring Systems:  Easy, Compliant, Supported
Out-of-the-box monitoring software may have its limitations, but it’s important to remember that it’s designed that way. Monitoring software must have 3 functions: recording, alarming and reporting. The complexity of each module needs to be assessed for your personal requirements, but typically you will be looking at a GAMP level 3 or 4 system only. One advantage of this type of system is it allows you to easily maintain a validated state during change control processes. Another advantage is that adding users and locations is relatively straightforward. In most systems, access and reporting is a breeze. However, there’s always something extra you would like to do and the inherent limitations of off-the-shelf software will sometimes thwart you. Perhaps the greatest advantage of ready-made is that, ultimately, it will keep you in compliance.  

Finally, off-the-shelf software generally comes with technical support that is faster than with customized systems. For one thing, there are no project files associated with specific sites. Also there are no specific quirks with installation and companies who create the software often offer solutions to simplify validation processes—such as IQOQ protocols—and validation services. In the end, it’s your project. The most important question you can ask yourself is:  where do you want to spend more time, debugging your software, or using it? A sledgehammer can be a useful tool, just not in a walnut processing facility.


About the Author
Jon Aldous is the Product Manager for Vaisala’s Life Science Division. His background is in Electronics and Electrical science and he holds a Bachelor of Engineering.  He lectured at the University of the West of England, teaching Digital and Mechanical Engineering and was involved with the development of poly-silicon micro structures for the use within thermopiles and intelligent data acquisition sensors.  After immigrating to the US, he worked for 12 years with Kaye Instruments as Product Manager developing that company’s thermal validation systems. He later joined Veriteq Instruments, which was acquired by Vaisala in 2010. The acquisition has enabled Aldous to expand his role into both software and hardware product management for life science applications.

Vaisala is a leader in providing comprehensive reliable, high-quality measurement and monitoring solutions in controlled environments within the life science industries. The company offers knowledge and education resources to customers so they are best prepared for an inspection, meeting FDA regulations and maintaining high quality specifically around the measurement and monitoring aspects of production and storage.

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