Inspection is considered a predictive maintenance technique. Visual inspection is the most basic condition monitoring technology out there, and relies on the observation of technicians or inspectors to determine the condition of an asset.

Many maintenance managers or reliability engineers claim that visual inspections are not taken into account in the predictive maintenance plan because it is already being executed outside the plan and they do not want to have duplication of tasks. This is quite common, however, that does not mean that visual inspection is not a predictive maintenance technique since with it we monitor the condition of the assets.

Visual inspections are often performed by production operating personnel, who usually take notes or make their inspection reports on paper. That paper typically ends up in a tray and is only retrieved or processed if an abnormality has been detected or if a work order or maintenance notice is generated.

Figure 3: Technician performing visual inspection on motor-pump groups.

The reason why visual inspection is not used in predictive maintenance plans can be very diverse and depend on each organization or company, but among the most common reasons are:

  • It is considered a maintenance activity that is already carried out by another department even though it is done for different purposes than to monitor the condition.
  • Visual inspections are reported on paper, so integrating the information is laborious and the effort is not usually compensated with the result obtained.
  • There is no information management system or predictive maintenance software to integrate visual inspection reports with other predictive maintenance reports.

Visual inspections do not require sophisticated instrumentation and software to perform. On the other hand, predictive maintenance hardware manufacturers are the main promoters of the technologies and their use in the industry. Therefore, behind visual inspections, there are no hardware manufacturers that promote the use of this technique for monitoring asset conditions.

It is a fact that visual inspections are a predictive maintenance technology with which we can determine the condition of assets. Therefore, visual inspections must be included in our predictive maintenance plans, whether performed by our own predictive maintenance personnel or any other member of the organization.