profitability through Risk Based Inspection (RBI)
Introduction – why RBI? The deregulation of the power industry over the past few decades has created a competitive environment where there is a continual drive to increase profitability by reducing operating costs. This is not a new challenge, yet plant managers have to achieve this with limited resources, ageing plant and demanding operating regimes, whilst also trying to meet ever more stringent environmental and safety standards. Whilst traditional maintenance strategies have, on the whole, provided adequate safety, reliability and availability, there is an increasing interest and trend towards Risk Based Inspection (RBI). It’s been around for many decades, but it is only in recent years that operators of traditional thermal power plants have been looking at RBI as a way of optimising their maintenance strategy, to lower operating costs and increase plant performance and profitability.
By using RBI to augment maintenance and inspections plans, focusing finite resources on operational elements that could result in the most significant facility loss events, plant managers can ensure that their assets will have more availability, leading to greater opportunities to generate revenue. Furthermore, implementation of RBI generates a greater understanding of operating equipment’ strengths and weaknesses, thus avoiding many previously unforeseen and usually costly plant shutdowns from occurring.
Traditional maintenance strategies Traditional maintenance strategies are a combination of statutory, preventative and predictive maintenance practices that are used in an overall programme to maintain performance and avoid costly reactive maintenance and unsafe operating conditions. Traditional maintenance techniques can be summarised as:
This combined maintenance strategy is commonplace and provides adequate levels of equipment reliability and safety. However, it doesn’t always target resources at the most critical high risk plant equipment and can be wasteful when targeted at lower risk plant equipment.
RBI Overview As is common in an operating plant, a relatively large percentage of reliability issues are often associated with a small percentage of plant equipment. The aim of RBI is to evaluate the level of risk and optimise maintenance resources in order to provide the appropriate level of treatment for high risk and low risk plant equipment.
Although beyond the scope of this article, an RBI project has the following main steps:
In general, the level of risk is calculated in terms of the likelihood of an undetected failure occurring and the consequence of such a failure.
To evaluate and prioritise plant equipment according to the level of risk, an understanding of the criticality, design life, condition, operating life, ageing mechanisms, modifications and current inspection and maintenance programme results is required. This should be set against the estimated loss value which takes into account the asset value, loss of production and reactive maintenance costs.
Having prioritised the plant equipment according to level of risk, the maintenance programme can be optimised in terms of inspection interval, duration, scope and resource allocation. The objective is not necessarily to reduce maintenance costs (although this can be achieved) but to refocus efforts to improve plant performance and profitability.
Therefore when implementing an RBI programme, the following points should be observed:
An insurer’s view of RBI The RBI methodology was first developed in the petroleum and petrochemical industry in the early 1990s, with the nuclear power industry also being an early adopter. After decades of implementation in these industries, insurance risk engineers and underwriters are familiar with the RBI methodology, and when implemented effectively it is seen as a positive risk feature.
Insurers are concerned with the reasons for and results of implementing an RBI programme. The most common concern is a plant owner implementing RBI as a way to reduce maintenance activities to save money. Whilst this can be achieved over a period of time, the implementation and initial transition to an RBI programme can result in increased inspection work and resource requirements.
So no matter what combination of maintenance practices are adopted, the prudent risk engineer and underwriter will place the quality of the maintenance strategy at the top of their list of priorities. The key driver is not the combination of maintenance practices adopted, but how effective the strategy is in preventing losses - particularly large losses - that could significantly impact plant owners and insurers.
The final point which is frequently cited from Health & Safety Executive (HSE) literature is that in any implementation of RBI, “the safety concerns need to take precedence over other influences such as business interruption and loss of earnings”.
What next? Three key steps to effective RBI deployment As a risk manager or a senior facility manager, it makes good business practice to implement RBI. In order to develop or evaluate an existing programme there are three key initial steps that are recommended:
Addressing these three points will create a platform for success and set your organisation in strong shape to realise the full benefits of RBI.
Paul Watson is a Risk Control Engineer at Willis Towers Watson Natural Resources in London.
