Automatic calculation of equipment availability to optimise maintenance policies and control efficiency

This article presents the AVAIL solution, developed by SUEZ during a pilot study carried out at a wastewater treatment plant (WWTP) with a 95,000 population equivalent capacity in 2014.

AVAIL enables the automatic calculation of reliability, service ability and availability (uptime) indicators of electromechanical equipment based on monitoring data. These automatic indicators are valuable decision-making aids for:

• Operators, for the purpose of measuring the results of their maintenance policies and having objective information at their disposal for ongoing enhancement
• Plant owners, in order to guarantee the level of service provided by operators and to analyse whether plant results over time are in line with expectations

In this way, all the conditions for a relationship of trust between partners are in place. Operators can optimise operations at the facility and owners can be sure that they receive a quality service.


The interests of WWTP plant owners and operators diverge in the area of maintenance. In effect, in relation to the maintenance and conservation of their facilities, owners can legitimately ask the question: “Is the provider doing enough?”

In contrast, the service provider might well address the matter from the opposite angle: “Am I not doing too much?” This divergence highlights a patent need for objectivity in the evaluation of the maintenance policy and the status of facilities, for the benefit of the two parties.

But how can the status of electromechanical equipment be measured objectively? In truth, there is no simple, unequivocal answer to that question.

SUEZ uses an objective method based on 4 criteria: performance, external signs of degradation, obsolescence and availability or uptime. The latter criterion encompasses two main components: reliability and serviceability.

Availability, reliability and serviceability indicators are vital because they transmit important information on the state of electromechanical equipment and reflect its behaviour. They also provide information on the quality of the maintenance service provided (quality and speed of operations).

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Article published in: FuturENVIRO #39 April 2017