The EMS may be a software module in an FMS or BMS or a separate stand-
alone application. An EMS usually provides a group of applications to optimize
a facility’s energy usage and costs. This may include the following programs:
n Tracking of utility bills to monitor usage and costs as well as comparing
projected, budgeted and actual usage and costs
n Comparing the energy usage to other similar buildings, an exercise
known as “benchmarking”
n Calculating the effect of thermal comfort or lighting alternatives. That
is, the cost for different lighting control strategies, proper ventilation
rates, and related elementsBecause energy can be saved by ensuring that equipment is operating in the
most cost-effective manner an EMS may have a feature to ensure proper mainte-
nance of mechanical and electrical equipment. Maintenance can be scheduled at
regular intervals based on historical data or manufacturer recommendations, or
equipment can be monitored to determine abnormal operating conditions.
Monitoring requires setting acceptable operating ranges for equipment and
then setting alarms for when the equipment operates out of range. Equipment
indicators that may signal possible malfunctions include the following:
n Temperature
n Vibration
n Pressure
n Air quality
n Humidity
n Energy consumption
n GasesComputerized Maintenance Management Systems
Computerized maintenance management systems (CMMS) are comprehensive
software applications for a variety of equipment and materials. Like EMSs,
a CMMS implementation can be a standalone application or integrated with
a software module of a larger FMS. The CMMS is probably the most essential
and expensive part of an FMS.
The CMMS integrates or communicates with the FMS to retrieve data from
field devices in determining when equipment or materials require maintenance.
Facility Management Systems 135