Failure Mode Analysis and How It Impacts Your Strategy

Transcription

1 Failure Mode Analysis and How It Impacts Your Strategy Helen Ramsey, National Asset Manager Utility Services, Downer, Auckland Abstract Asset owners want to clearly understand what drives reactive expenditure and the causes of asset failure in order to effectively target maintenance programmes. When failure modes are well understood by a review of historic maintenance records, then sound strategies can be developed to align to business strategy. In some cases it may be acceptable to have a high level of reactive expenditure. Modern Asset Management Systems are about reducing the friction between the data and users so that engineers can focus on improved solutions. The key to gaining benefits from any asset management system (or job management system) is the analysis of the data captured. Being able to visualise that information makes it more available to users. Too often significant amounts of data is captured and never effectively analysed to realise benefits in improved operational performance or targeted renewal programmes. The data may not be captured in a consist manner to analysis. However, this should not be used as a reason not to clean the data ready for analysis. Providing evidence based decision making and validating field observations. The key behind strategic asset management is a transparent line of sight which includes network needs, predictive modelling, forward works programmes and an agreed/delivered outcome. All this will provide confidence and auditability for network funders and decision makers. Key Words Failure Mode Analysis Strategy Data Analysis Maintenance Programme

2 Introduction Many organisations have Asset Management Plans and Long Term Plans in place with associated financial projections for expected capital and operational expenditure to maintain core infrastructure. But how reliable and detailed are these plans. Often these plans are prepared in isolation from operational and maintenance staff with little detailed understanding of what drives asset failure and expenditure requirements. A number of organisations have asset management and or job management systems but how accurate and reliable is the data held within them and is that data ever analysed to inform core strategy. Downer has been working closely with a number of customers to close the gap between operations and planning. Ensuring that core historic maintenance data is effectively analysed to understand what drives the failure of their specific assets. This is then used to develop targeted maintenance programmes achieving the best balance between planned and reactive work for their specific environment. Noting that there can be a point where assets become unmaintainable if they are in very poor condition and the level of reactive work is significantly greater than planned. Failure Mode Analysis Background Failure mode and effects analysis (FMEA) also "failure modes was one of the first highly structured, systematic techniques for failure analysis. It was developed by reliability engineers in the late 1950s to study problems that might arise from malfunctions of military systems. An FMEA is often the first step of a system reliability study. It involves reviewing as many components, assemblies, and subsystems as possible to identify failure modes, and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA worksheet. FMEA is at the heart of reliability centred maintenance programmes. FMEA is a qualitative and systematic tool, to help anticipate what might go wrong. In addition to identifying how failure might occur and the effects of that failure, FMEA also helps find the possible causes of failures and the likelihood of failures being detected before occurrence. Used across many industries, FMEA is one of the best ways of analysing potential reliability problems early to take quick action and mitigate failure. The ability to anticipate issues early allows to design out failures and design in reliable, safe and customer-pleasing features. Table 1 describes the three key factors to score. After ranking the severity, occurrence and detection levels for each failure mode, the team will be able to calculate a risk priority number (RPN). Severity Description Severity ranking encompasses what is important to the industry, company or customers (e.g., safety standards, environment, legal, production/ service continuity, scrap, loss of business, damaged reputation) Occurrence Rank the probability of a failure occurring during the expected lifetime of the product or service Detection Rank the probability of the problem being detected and acted upon before it has happened Table 1: RPN Score The RPN score is then used to rank and prioritise actions. The prioritisation process allows Corrective Actions to be ranked for completion and to focus efforts. Corrective Actions being the most basic cause (or causes) that can reasonably be identified that management has control to fix and, when fixed, will prevent (or significantly reduce the likelihood of) the problem s recurrence.

3 The key to the RPN score is to accurately assess how likely you are able to detect a fault before failure occurs and what the consequences are if you don t detect the fault in time. For some assets being able to effectively respond to an asset failure to reduce the consequence of failure maybe an adequate action. The prioritisation process is based on Pareto rule. Typically, 80 percent of issues are caused by 20 percent of the potential problems. As a rule of thumb, teams can focus their attention initially on the failures with the top 20 percent of the highest RPN scores. After the completion of the first cut of Corrective Actions it is important to reassess the RPN as part of the continuous improvement process. Data Analysis The first step in any good asset management strategy is to have a thorough understanding of your assets, detailed register, their value, condition, performance, and criticality. The potential risk faced in terms of asset failure and likely cost implications, how resilient are the assets. Most infrastructure managers and owners know this but what does that mean in detail. Most asset owners capture some level of financial data about spend on their assets from the date they were constructed or ownership acquired. Have undertaken some form of inspection of the assets in an adhoc or programmed basis. However, how often these data sources are analysed and reviewed, how structured the information is captured and stored is key. If asset owners want to manage their risks effectively they need robust processes around data capture and analysis and implement some form of failure mode analysis to support the asset planning and strategy framework. It is only through the detailed analysis of historic expenditure and reactive work that you can start to get a better understanding of key causes of failure within a particular network or portfolio. Understanding and identifying expenditure trends early and potential impacts on budgets. Tracking demand trends and change in usage is also critical to align maintenance budgets and key asset strategies. The key is to have a strong linkage between operations and planning with good systems to visualise operational data. Targeted maintenance Often planned and programme maintenance is continued without any review of how effective they are. They are not targeted to critical assets or sites with high utilisation. Condition inspection programmes can be cut to save money. When this occurs it often leads directly to a more reactive maintenance situation. This can lead to key risks not being effectively managed and potential cost implications. To support maintenance contracts Downer have invested significantly in the development of a process-driven Integrated Maintenance Management System (IMMS). Figure 1 depicts how our advanced IMMS works. The top-level process begins with the development of strategic objectives and Critical Success Factors, and shows how specific maintenance strategies can be implemented to achieve the desired outcomes. The process for managing condition and defects is at the heart of asset maintenance management. Figure 1: IMMS Map Those charged with carrying out Condition Assessments (Inspector and operational field staff) will use a visual assessment guide as a benchmark to assess a defect against the contract Levels of Service.

4 They will record a defect Severity based on an assessment of each defect, a primary cause, and an initial proposed repair treatment. Preventative Maintenance (PM) will always be recorded as Severity 4 (S4) in order to promote it in line with stated objectives. A safety issue, or an audit nonconformance, will always be recorded as Severity 5 (S5) to ensure they are prioritised and programmed accordingly. Figure 2: Defects Management Process Defect Management Process, which controls how defects are ranked, prioritised and programmed. This is at the heart of our operational approach to achieving costeffectiveness whilst delivering on the defined strategies. We have adopted the condition and performance assessment prioritisation (Severity) guidelines from the National Asset Management Support (NAMS) group (2011) incorporating industry standards/ measures where relevant being: Very good condition - No defect is measured / recorded (monitor only). Minor defect - Identified defect is above the Level of Service but is recorded and is only being monitored, use industry measures to monitor performance, such as minor rust on building gutter. The threshold for data capture is that it would be corrected as part of an exterior repaint. Moderate defect - Defect is safe and is above the LoS for the contract. However if a similar activity was programmed nearby these repairs would be considered for repairing. Requires intervention - Defect is now a Fault as it is below the requirements of the LoS and requires intervention within the appropriate response time. It has now become a Fault. Unsafe Fault requires an immediate intervention through temporary repair or site management. Evidence based decision making The key behind strategic asset management is a transparent line of sight which includes network needs, predictive modelling, forward works programmes and an agreed/delivered outcome. All this will provide confidence and auditability for network funders and decision makers. The challenge is around data quality management when multi parties are involved in capturing the base information to support data analysis. Figure 3 depicts the importance of core data to inform and drive strategic asset decisions. Figure 3: Value Pyramid Outcomes of Data Analysis Recent detailed data analysis of historic information on facilities expenditure for different customers has revealed some interesting observations. While expensive plant items like HVAC systems are generally seen as major expenditure items due to high replacement costs. What drives expenditure that is often overlooked is assets that people interact with (doors, locks, catches handles, bathroom fixtures). These items always feature in the top expenditure category for building assets whether office spaces, public facilities or industrial locations. There is a direct correlation between utilisation and expenditure particularly in regard to property assets, whether a public

5 facility or office building the more people that utilise the facility the higher the reactive expenditure. Likewise the highest expenditure of water supply assets is the high volume service connections, meters, tobies, while burst water mains and pump repairs are expensive to repair or replace they are often not the highest expenditure items overtime. They certainly aren t the highest frequency items. Understanding what assets fail more frequently than others and what drives their cause of failure enables targeted maintenance strategies to be deployed. This ensures that resources (labour, plant and materials) can be aligned to network needs and demand. This also highlights the need to standardise common fittings. In the facilities space too often large portfolio owners fail to capitalise on potential savings from utilising standard fittings for items such as door locks, catches, handles, bathroom fixtures. During the construction phase it is easy to look for savings by installing cheaper fixtures and fittings when budgets are tight. We all know that these decisions end up being more expensive from a whole of life perspective. This highlights the need for large portfolio owners to have a strong link between capital projects teams and operations. Value engineering practices should be around what is best across the portfolio. Conclusion Fundamental Asset Management principals have been around for a long time. Failure mode analysis is a key technique to understand how a particular asset or network performs in that specific environment. It should be used to inform detailed maintenance strategies that target the specific needs of a particular network or portfolio. Where key historic data sources such as job management and asset management records are analysed in detail they provide valuable insights into what has and is likely to drive expenditure in the future. Too often this process is overlooked with maintenance programmes being rolled over year on year without a thorough understanding as to whether they are cost effective and adding value. As networks age and demand on the infrastructure changes the balance between reactive and planned maintenance expenditure will vary. Only through detailed analysis of trends, failure modes and condition will asset owners be able to cost effectively manage their infrastructure assets and associated risks. Acknowledgments, References Bevins A. K., Fon Sing P., Mortimer P.F. Integrated Maintenance Management System (2015) Author Biography Helen is Chartered Civil Engineer with over 27 years experience, including senior management roles within local authorities, consultancies and contractors. She has a strong background in asset management, maintenance, contract management, financial management, supply chain and operational effectiveness, across a range of utility services. This has given her a very broad background and the ability to build strong working relationships. At Downer Helen works collaboratively across the Infrastructure Services team, developing and implementing the asset management strategy and initiatives within the utilities business (Water, OSM and FM). She is focused on continuous improvement in the delivery of operations and maintenance contracts.