Reliability engineering is the discipline of ensuring that a system will be reliable when operated in a specified manner. Reliability theory is the foundation of reliability engineering. For engineering purposes, reliability is defined as the probability that a system will perform its intended function during a specified period of time under stated conditions. Reliability engineering is performed throughout the entire life cycle of a system, including development, testing, production, and operation.
The function of reliability engineering is to develop the reliability requirements for the system, design the system or product to meet the reliability requirements, establish an adequate reliability program, and perform appropriate analysis to monitor the actual reliability of the system or product during its life. Reliability improvement can be thought of as a process, and Exponent can provide assistance with any or all of the main elements of that process, which are:
- Reliability strategies
- System or product design
- Failure modes and effects analysis
- Reliability modeling and estimation
- Reliability testing (accelerated life-cycle tests)
- Quality assurance strategies
- Work management and execution
- Continuous improvement
With experience in analyzing thousands of failures, Exponent provides unique and advanced services in performing risk and reliability assessments. The primary focus of our scientists and engineers is assisting our clients in minimizing bottom-line losses in their business or operation. Accidents, unanticipated events, and system failures are the primary causes of deferred or lost production interruptions and may lead to loss of life, injury, property damage, and undesired releases. Exponent’s multi-disciplinary staff has performed diverse technical, business-interruption, and compliance-related risk and reliability assessments for chemical, petrochemical, petroleum, and manufacturing clients worldwide.
Reliability strategies involve a structured approach to identifying critical equipment and systems. This could include a failure mode and effects analysis to identify the critical component or system failure modes. A mean time to failure (or between failure for repairable systems) model can also be used to derive a probabilistic reliability model. Defining the appropriate maintenance regimen and replacement strategies based on that criticality determination is also part of a well-designed reliability program. When done properly, this element leads to optimal reliability. Our staff uses traditional and innovative situation-specific methods and tools to identify risk scenarios and their causes, consequences, and likelihood. This enables further quantification and prioritization of technical and business risks. Exponent lets the client’s need dictate the methodology. The methods include Preliminary Hazard or Risk Analysis (PHA/PRA), Layer of Protection Analysis (LoPA), Failure Modes and Effects Analysis (FMEA), Mechanical Integrity Assessments, Hazards and Operability Study (HAZOPs), Fault Tree Analysis (FTA), Human Error Analysis, and others. Exponent supplements these methods with risk quantification using probabilistic and uncertainty principles, and decision analysis. Our staff performs risk analysis ranging from compliance to total business-based approaches and addresses a number of issues critical to the operation a facility. These issues include:
Economic Risks and Benefits
Engineering-economic studies of operational risks and costs are performed. Costs for alternative safety mitigation/quality control measures and the risk reduction or quality improvement potential for each alternative are evaluated to identify optimal measures.
At various levels (component, subsystem, system, plant), risk management analysis can assist in design, operation, feasibility studies, scheduling, budgeting, and revenue allocation. Properly integrated analysis can be modularized at any desired level, resulting in useful information to aid decision making.
Operational Reliability
Factors affecting production operations are analyzed to evaluate the risk of breakdown and production stoppage. Such factors include reliability, performance, and adequacy of structures, equipment, control systems, and operating and maintenance procedures. Detailed analysis of critical structural systems and process equipment are performed as necessary.
Safety Hazards
Plant personnel safety, as well as public safety issues, are analyzed to identify potentially significant health and safety risks. These include risks of environmental release of hazardous chemicals, fire and toxicity hazards, and emergency response plans.
Product Quality
Factors affecting product quality are analyzed to reduce the potential of product batches being manufactured out of specification. These include process control ranges, statistical sampling, and quality assurance testing programs. Work execution includes the identification of work to be performed, as well as the planning, scheduling, and performance of that work. This is part of an overall quality assurance or quality control program. When done properly, this element leads to optimal resource utilization.
Continuous Improvement
Continuous improvement is the process by which an organization learns from the performance of each in the process and applies that knowledge to improve effectiveness and efficiency through each process cycle. It includes proper work closeout procedure, as well as a comprehensive corrective action program (and culture), bolstered by a robust root-cause analysis program. The proper application of metrics and/or key performance indicators also play a key role in this element.