Since time immemorial, the maintenance of tools and equipments has been taken care of by the users when it was no longer possible to run them. This was termed as “Breakdown or Reactive Maintenance”. It was followed by the “Preventive Maintenance” in 1950s. It was time-based maintenance, featuring periodic servicing and overhaul to prevent damages of the equipments (Nakajima, 1988). Although it helped reduce down-time, it was an expensive alternative as many parts were replaced periodically, while they could've lasted longer.