Predictive maintenance (PdM), also known as condition-based maintenance, is one of the hot topics when discussing the application areas of industrial IoT and smart factories. But what is IoTbased predictive maintenance and what are the benefits?
Maintenance has always been an intrinsic part of any production. A good maintenance plan ensures safe operations, equipment availability and reduces costs. Maintenance includes the troubleshooting, repairing, controlling and verifying physical equipment, and contributes to the improvement of industrial processes. According to Gouriveau et. al., the last 20 years have meant new requirements for maintenance in terms of quality, safety and costs. As industrial equipment become more complex, they requires greater competence in maintenance as well. 
Predictive maintenance techniques are used to determine when in-service equipment need repairment. PdM is based on real-time analysis of data from the industrial equipment . The objective is to prevent unexpected failures without costly and inconvenient routine checks, or any unnecessary downtime.
Predictive maintenance requires condition monitoring. This means the continuous monitoring of machines during process, to ensure optimal use. Condition monitoring can be done continuously, periodically and remotely. First, production or machines are monitored continuously, with data collected on critical moments. Periodic monitoring gives analysis over the changing vibration behaviour. And finally, remote monitoring enables the equipment to be kept an eye on from a remote location. 
Data collection and processing is one of the main components of PdM. The data collected can be based on physical phenomena such as vibration, temperature, pressure, voltage, light dispersion or humidity. Other kind of data can be, e.g. process deviations, raw material quality, control settings, or machine specification. Technology has made it possible to monitor machines and equipment continuously. This is done by using different kinds of sensors to assess the degradation and predict the failures ahead of time.  In recent years, the the availability of wireless industrial internet of things (IIoT) devices has made the process and setup easier and faster.
Read how Haltian’s wireless IoT sensors are used to monitor connecting components in electrical substations here.
WHY IoT-BASED PREDICTIVE MAINTENANCE?
The benefits of predictive maintenance are vast, and differ from case to case, but here are some of them listed:
- Reduction in the number of breakdowns
- Increased reliability of production processes
- Improvement of personnel safety
- Reduction of periods of inactivity for the equipment
- Incresed performance of the company
- Increased equipment lifetime 
PREDICTIVE OR PREVENTIVE MAINTENANCE?
HOW TO GET STARTED WITH IOT-BASED PREDICTIVE MAINTENANCE?
 R. Gouriveau, K. Medjaher and N. Zerhouni, From Prognostics and Health Systems Management to Predictive Maintenance 1: Monitoring and Prognostics, 2016
 “Condition Monitoring of rotating machines,” [Online]. Available: https://www.istec.com/en/condition-monitoring-rotating-machines/
 N. Amruthnath and T. Gupta, “Fault Class Prediction in Unsupervised Learning using Model-Based Clustering Approach,” 2018.