BMS and EMS

A Building Management System (BMS) is also known as a Building Automation System (BAS). A BMS is a computer-based control system, consisting of both hardware and software, installed in buildings that control and monitors the building’s mechanical and electrical equipment (heating, ventilation and air conditioning (HVAC), lighting, power systems, fire systems…). Traditionally, the BMS measurement devices are low grade, low cost sensors (±5%rh accuracy) with no data logging or redundant power options.

Typically, a BMS is subjected to Good Engineering Practices (GEP).

An Environmental Monitoring System (EMS) is a computer-based monitoring system, consisting of both hardware and software, installed in buildings to monitor the environmental conditions (temperature, relative humidity, pressure…) in specific areas ensuring that their design requirements are met and that they are fit for their intended use. The EMS can be an integral part of the BMS or it can be independent. But the EMS can be seen as a backup of the BMS in terms measurement data availability.

Typically, an EMS is subjected to Good Manufacturing Practices (GMP).

The ISPE GAMP®5 Guide: A Risk-Based Approach to Compliant GxP Computerized Systems is regarded as the definitive industry guidance on GxP computerized system compliance and validation for companies and suppliers and is referenced by regulators worldwide and apply to both BMS and EMS if they are used within a GxP application. Risk management is also an integral part of Good Engineering Practice (GEP), regulated users have product and process knowledge and the specification and design of a system should be carried out where risk management is applied to identify and review risks (ICH Q9) and to remove or reduce them to an acceptable level.

Within a regulated industry, the BMS controls defined Critical Control Parameters (CCP’s) to ensure that product quality is optimal. One key risk within the BMS is that a measurement device fails, and no backup exists, meaning that no CCP data is available.

Monitoring of these CCP’s within the EMS helps reduce this identified risk. If the BMS device fails and the environmental conditions change, the EMS will inform the users. If the EMS measurement device fails, the user will also be notified, but in most cases the BMS measurement device will still be operation so critical data is always available.

Here is it important to point out that the stakeholders that the define the User Requirement Specifications (URS) of the BMS and the EMS are different. Whereas the BMS covers many areas and applications leading to a longer more complicated and specific URS, the primary requirements of the EMS is monitoring, alarming and reporting.

The GMP guidelines state that the facilities and equipment should be monitored and validated. It is possible to use the a BMS to monitor a GMP application, but this means that the BMS is subjected to GMP guidelines and must be appropriately validated. As the BMS controls the complete facility, including GMP and non-GMP areas, quite some time can be spent on doing a complete system validation, especially with the already more complicated URS. It is possible to create two independent systems (separate hardware, networks, databases), one for GMP and one for non GMP, but this also generates additional costs. An EMS system will only monitor GMP areas and has the advantage that equipment not linked up to the BMS can also be monitored (freezers, fridges, incubators, climatic chambers…).

Certain regulations, such as the EU Annex 1 for example, state that the monitoring and recording systems (EMS) should be independent of the controlling system (BMS) and as of such, it is crucial to review the regulations as well as carrying out the risk assessment.

Any changes made to a validated system need to be done following a defined change management process. Within the BMS, any changes made to the non-GMP area will also require the same change management.

Rotronic offers hardware for both BMS and EMS applications:

• HF1: Low cost HVAC transmitter.
• HF5 with the HC2A-S probe: Transmitter with interchangeable digital probe.
• RMS-LOG-L with the RMS-HCD-S: Data logger with interchangeable digital probe. LINK: USING THE MODBUS TCP AND HTTP PROTOCOLS CONCURRENTLY.

One key feature that Rotronic offers is digital sensors with adjustment and calibration data stored directly on the sensor. Digital sensors enable simplified and enhanced calibration possibilities for the regulated user:

• The digital measurement probe is attached to a data logger/transmitter.
• The digital measurement probe is replaced with another digital probe for the yearly calibration.
• The digital measurement probe is calibrated. When it is out of tolerance, then the user can carry out a custom adjustment (Offset). The calibration and adjustment data is stored on the digital probe.
• After calibration, the probe is returned to the original data logger/transmitter.

The data logger/transmitter remains installed, the replacement measurement probe accurately ensures that the CCP data is being collected and correctly processed.

For calibrations, Rotronic offer a range of generators and references:

• HygroCal100
• HG2-S
• HG2-XL
• S8000

For BMS applications Rotronic offers transmitters with an analogue or digital output. The BMS will process the signal to ensure the correct environmental conditions. The digital probes can also be set as simulators to test the instrument loop.

For EMS applications Rotronic offers data loggers. The data loggers send data to the Rotronic Monitoring System (RMS) software via the local area network (LAN). Furthermore, the reduce the risk even more, the data loggers have a backup battery, meaning that even if no power, or network connection is available (the user will be notified via the system), the data logger will still collect the critical data and send it to the RMS software once connection and power are available again.