Editing Maintenance (section)

==== Condition-based maintenance ====
'''Condition-based maintenance''' ('''CBM'''), shortly described, is maintenance [[Maintenance, repair and operations|when need arises]]. Albeit chronologically much older, It is considered one section or practice inside the broader and newer predictive maintenance field, where new AI technologies and connectivity abilities are put to action and where the acronym CBM is more often used to describe 'condition Based Monitoring' rather than the maintenance itself. CBM maintenance is performed after one or more indicators show that equipment is going to fail or that equipment performance is deteriorating.

This concept is applicable to mission-critical systems that incorporate [[active redundancy]] and [[fault reporting]]. It is also applicable to non-mission critical systems that lack redundancy and fault reporting.

Condition-based maintenance was introduced to try to maintain the correct equipment at the right time. CBM is based on using real-time data to prioritize and optimize maintenance resources. Observing the state of the system is known as [[condition monitoring]]. Such a system will determine the equipment's health, and act only when maintenance is actually necessary. Developments in recent years have allowed extensive instrumentation of equipment, and together with better tools for analyzing condition data, the maintenance personnel of today is more than ever able to decide what is the right time to perform maintenance on some piece of equipment. Ideally, condition-based maintenance will allow the maintenance personnel to do only the right things, minimizing spare parts cost, system downtime and time spent on maintenance.

=====Challenges=====
Despite its usefulness of equipment, there are several challenges to the use of CBM. First and most important of all, the initial cost of CBM can be high. It requires improved instrumentation of the equipment. Often the cost of sufficient instruments can be quite large, especially on equipment that is already installed.  Wireless systems have reduced the initial cost.  Therefore, it is important for the installer to decide the importance of the investment before adding CBM to all equipment. A result of this cost is that the first generation of CBM in the [[Petroleum industry|oil]] and gas industry has only focused on vibration in heavy rotating equipment.

Secondly, introducing CBM will invoke a major change in how maintenance is performed, and potentially to the whole maintenance organization in a company. Organizational changes are in general difficult.

Also, the technical side of it is not always as simple. Even if some types of equipment can easily be observed by measuring simple values such as vibration (displacement, velocity or acceleration), temperature or pressure, it is not trivial to turn this measured data into actionable knowledge about the health of the equipment.

=====Value potential=====
As systems get more costly, and instrumentation and information systems tend to become cheaper and more reliable, CBM becomes an important tool for running a plant or factory in an optimal manner. Better operations will lead to lower production cost and lower use of resources. And lower use of resources may be one of the most important differentiators in a future where environmental issues become more important by the day.

Another scenario where value can be created is by monitoring the health of a car motor. Rather than changing parts at predefined intervals, the car itself can tell you when something needs to be changed based on cheap and simple instrumentation.

It is Department of Defense policy that condition-based maintenance (CBM) be ''"implemented to improve maintenance agility and responsiveness, increase operational availability, and reduce life cycle total ownership costs".<ref>[https://web.archive.org/web/20140701070946/http://www.acq.osd.mil/log/mpp/cbm%2B/cbm_policy_memorandum.pdf CBM Policy Memorandum].</ref>''

=====Advantages and disadvantages=====
CBM has some advantages over planned maintenance:

* Improved system reliability
* Decreased maintenance costs
* Decreased number of maintenance operations causes a reduction of [[human error]] influences

Its disadvantages are:

* High installation costs, for minor equipment items often more than the value of the equipment
* Unpredictable maintenance periods cause costs to be divided unequally.
* Increased number of parts (the CBM installation itself) that need maintenance and checking.

Today, due to its costs, CBM is not used for less important parts of machinery despite obvious advantages. However it can be found everywhere where increased safety is required, and in future will be applied even more widely.<ref>{{cite journal | title=An enhanced diagnostic scheme for bearing condition monitoring | journal=IEEE Transactions on Instrumentation and Measurement| year=2010 | last1=Liu |author2=Wang, Golnaraghi | volume=59 | issue=2 | pages=309–321 | first1=Jie | doi=10.1109/tim.2009.2023814| bibcode=2010ITIM...59..309L| s2cid=1892843}}</ref><ref>{{cite journal | title=A review on machinery diagnostics and prognostics implementing condition-based maintenance| journal=Mechanical Systems and Signal Processing| year=2006 | last1=Jardine |author2=Lin, Banjevic | volume=20 | issue=7 | pages=1483–1510 | first1=A.K.S. | doi=10.1016/j.ymssp.2005.09.012| bibcode=2006MSSP...20.1483J}}</ref>