The desire to continuously improve the certainty of outcomes and control costs in marine and drilling asset operations is driving the need to improve the efficiency and effectiveness of inspection and test activities in asset selection and acceptance programs. The goals of any effective selection and acceptance program should be to identify the asset that is the best fit for the purpose of your intended operation and has the highest probability of completing those operations safely, on time, and on schedule.
While we often look at Non-Productive Time (NPT) as that probability indicator, the reliability of the operations and equipment is a much better predictor of performance. Reliability is defined as:
The probability that the equipment will perform its intended function, within stated conditions, for a specified period of time.
NPT is a record of past performance, which is a moderately good indicator of future performance. Reliability however is the true measure of future performance.
Traditional condition inspections and functional testing provide necessary situational awareness, i.e., they evaluate the capability of a system with respect to what is known at that moment. That awareness, however, is limited to the short-term performance of the systems inspected and the functions tested. There is limited insight as to performance over the medium to long term future, or for requirements that have not been specifically inspected or tested.
Adding a comprehensive evaluation of the reliability of the systems on the asset provides information about the operational integrity, which is the ability to manage the operation in a manner that ensures continued good performance and continuous improvement. Reliability provides medium to long term insight to the equipment systems ability to continue to function over time, and more importantly function over the time you have it under contract.
There are specific reliability metrics, including Mean Time Between Interrupt (MTBI), Mean Time Between Failure (MTBF), and Mean Time Between Assist (MTBA). For systems such as well control, where operational cycles are more important than time, mean cycles rather than mean time can be used. However, metrics can be misleading. The reliability of the metrics themselves must be established before they can be used as a measure of the reliability of the systems. Reliable data is necessary before we can evaluate system reliability.
Reliable data has two characteristics:
- It is the outcome of an efficient and effective operations and maintenance processes, and
- It exhibits strong statistical correlation over time
In order to evaluate the efficiency and effectiveness of the operations and maintenance process Athens Group Services looks at five critical characteristics:
- Up-to-date operational, maintenance and repair procedures that are consistently and rigorously applied in practice,
- Specific goals for a reliability baseline and improvement,
- A data acquisition and analysis system with the data quality and quantity necessary to measure and understand the reliability of the operational, maintenance and repair systems,
- The proper levels of human capital, technology, and automation necessary to support the measurement, analysis, and implementation of reliability baselines and improvements, and
- Ongoing subject matter expert advisory and execution resources to identify, implement, and manage the reliability program.
For the statistical correlation, Athens Group Services implements a “measure, stabilize, characterize” data engineering analysis. This analysis looks for evidence that the correct measurements are being made, these measurements are indicative of a stable process, and the process is well understood.
Athens Group Services’ two-step reliability evaluation services implement proven cross-industry standards and guidance for reliability, availability, and maintainability. We focus on evaluating metric reliability and system reliability, which provides you with the information necessary to make the best selection and acceptance decisions. Contact us if you want to add reliability evaluations to your marine asset selection and acceptance programs.
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