Thinking beyond Rigid Scheduled Maintenance
Guest post by
Abhishek Prasad Verma, Lead Consultant, Oracle Practice, Enterprise Solutions, Infosys
Assets are the lifeline for a Power Utility Company. Considerable amount of money is spent in ensuring their availability, longevity and efficiency for power generation/transmission or distribution as this has a direct impact on the top-line and bottom-line of any company. Assets not maintained well can result in accidents causing huge indirect losses in form of penalties and/or compensation.
Traditionally companies have relied on fixed rigid scheduled maintenance where an asset like a distribution transformer is periodically inspected and maintained. This looks simple in theory, but is practically a much costlier affair. It is taxing in terms of resource planning, impractical because of huge number of assets on the field (A distribution company supplying electricity to 7 million consumers would have around 140 thousand distribution transformers on the field) and often ineffective as it focuses on duration of operation rather than fault behavior, operational parameters and root cause trending. Traditional method of maintenance was the only option when there were no systems in place, but now with specialized packages available for utilities, it's time to look at other more intuitive, efficient and cost effective methods of maintenance.
Alternative ways to increase reliability while reducing the cost of needless and sometimes regressive maintenance services is to use Condition Based Maintenance (CBM) and Reliability Centered Maintenance (RCM).
CBM uses visual inspection and performance data to assess asset condition and suggests maintenance only when warranted. Information Technology can be used to define operational tolerances for important measurable parameters and trigger maintenance when the instantaneous parameters go beyond the preset tolerances. Improved knowledge of failure mechanisms, advancement in failure forecasting techniques and automatic capturing of key operational parameters through sensor devices in a smart grid help improve understand and define maintenance interval for CBM.
One of the disadvantages in CBM is that all assets in the same technical condition are treated in the same way i.e. it does not take the importance of an asset in the network/process in account. Hence RCM that combines 'technical condition' and 'importance in network' is often used as an additional tool. RCM is an intelligent logical decision making process to develop effective and efficient maintenance based on the recognition that maintenance requirements of assets are determined by their "function" within the system and on the "consequences of failure". Using FMEA (Failure Mode and Effects Analysis) i.e. prioritization of failures according to how serious their consequences are, how frequently they occur and how easily they can be detected, RCM can be used to group assets and devise an effective and efficient maintenance strategy.
To conclude, it is important to look maintenance in a holistic fashion and use a combination of maintenance strategies depending on importance of assets in the system/process, consequence of failure, cost-benefit analysis and amount of risk an organization can take without adversely impacting revenue or customer service.
