Visite nuestro sitio en Español: Confiabilidad.net    RSS | Contact

Articles: Reliability Engineering

Failure Mapping

A New And Powerful Tool For Improving Reliability And Maintenance by Daniel T. Daley

Excerpt courtesy of Industrial Press Inc.

 

Failure Mapping is a system that recognizes patterns of events or conditions that have a direct relationship with subsequent failures. The ability to describe the meaningful elements of those patterns with high accuracy and then to recognize the relationship between them and a failure depends on the ability to capture simple unadorned facts. This book describes a process that fills those needs more completely than other approaches by detailed examination of events, a process that is known as Failure Mapping.

Failure Mode and Effect Analysis - FMEA

Failure mode and effect analysis (FMEA) is the study of potential failures that might occur in any part of a system to determine the probable effect of each failure on all other parts of the system and on probable operations success. When criticality analysis is added for sophisticated studies the method is know as FMEAC. In the automotive world where FMEA is a required portion of the quality systems, it is frequently known as PFMEA for potential failure mode and effect analysis. The basic thrust of the analysis tool is to prevent failures using a simple and cost effective analysis that draws on the collective information of the team to find problems and resolve them before they occur.

Failure Rates

Failure rates, in the simplest form, are S(time in use)/S(number of failures) or the reciprocal of mean times to/between failure. For more sophisticated failure data bases such as Weibull data bases the failure rates can be disclosed without giving away proprietary data such as the shape factors, beta, which tell the failure mode for the equipment.

Fault Tree Analysis

Fault tree analysis (FTA) is a top down processes of defining the top level problems and through a deductive approach using parallel and series combinations of possible malfunctions to find the root of the problem and correct it before the failure occurs. The reliability tool can be used as qualitative or quantitative methods.

FRACAS – Unleashing the Power of the EAM as a Reliability Improvement Tool

Note: Originally presented by Bill Keeter, Allied Reliability, at EAM-2006 The Enterprise Asset Management Summit in Las Vegas

A strong Failure Reporting, Analysis, and Corrective Action System (FRACAS) is the backbone of a good asset performance improvement effort. The FRACAS provides the business elements required to close the loop on Root Cause Failure Analysis (RCFA) and Reliability Centered Maintenance (RCM) efforts. The FRACAS changes RCFA from what are often one shot exercises to a managed program for systematically improving equipment and process performance. This chapter describes the basics of implementing the FRACAS and how to use it to insure implementation of RCFA recommendations.

FRACAS Systems

Failure reporting and corrective action systems (FRACAS) is an organized database for aiding in solving reliability problems using a common sense approach by systematically and permanently removing failure mechanism. Good historical data from this system can populate a Weibull database.

Highly Accelerated Life Test - HALT

Highly accelerated life test (HALT) is an offspring of older environmental stress screening (ESS) tests and it is a testing process for ruggedization of pre-production products by heavily stressing the product to identify failure modes quickly and to verify weak links in the system.

Highly Accelerated Stress Screen - HASS

Highly accelerated stress screen (HASS) uses the same stresses as HALT, but at a lower stress level. Compared to HALT testing, temperature and voltage extremes may be reduced by 10-15%, vibration levels reduced 50%, etc. depending upon the design although all the stresses may be above rated product specifications with the motivation to produce test results quickly for verifying product compliance.

How Sterling Steel Increases Equipment Availability and Throughput

Sterling Steel produces 450,000 tons of wire rod for its parent company, Leggett & Platt. The long products mini mill utilizes a 415 ton Electric Arc Furnace; two Ladle Metallurgy Facilities; an eight strand Billet Caster and a single strand Rod Mill to produce the wire rod for Leggett & Platt's Wire Mills.

How to Set Up a Reliability Management System

What to do

Launch a reliability improvement drive as a mission for the whole organisation and develop a robust organisation aimed to sustain the pro-active and reactive reliability efforts on the lines of an Operational Reliability Management System.

Improving the Reliability of a Turbofan Jet Engine

By Larry Tyson

Our team is directly involved in the reliability, availability, and maintainability (RAM) of a turbo fan jet engine. The engine fuel controller (FC) is one of the main components on the engine. Its purpose is to control the flow of fuel based on pilot demand from the throttle levers in the aircraft cockpit. If the FC does not operate properly, the engine does not receive fuel in accordance with pilot demand and may shut down. As can be imagined, shutting down an engine is not a good situation in flight.Improving the Reliability of a Turbofan Jet Engine by Using the Weibull Distribution for Failure Mode Analysis (WFMA)

NOTE: FM = FAILURE MODE, MAL CODE = MALFUNCTION CODE, they are the same

Integrated Reliability Tools Give Asset Managers Decision Making Power

Asset managers are able to use reliability simulation packages to make informed decisions on managing their assets to achieve their business goals. Integration has been a key feature of recent developments between Reliability methods and also between the integrated package and Enterprise Reliability Systems. Integration between methods in the Availability Workbench package means that RCM analysis is integrated with Weibull data analysis, the RCM is integrated with Reliability Block Diagrams and both are linked to Lifecycle costs calculations. Integration with Enterprise asset Management such as SAP, Mincom Ellipse and IBM's Maximo provides the means to use the source data held in the Enterprise System to make proactive decisions and store the outputs of the reliability decision making system in the
Enterprise system.

Introduction to Reliability Engineering

What is Reliability Engineering?

No one disputes the need for articles to be reliable. The average consumer is acutely aware of the problem of less than perfect reliability in domestic products such as TV sets and automobiles. Organizations such as airlines, the military and public utilities are aware of the costs of unreliability. Manufacturers often suffer high costs of failure under warranty. Argument and misunderstanding begin when we try to quantify reliability values, or try to assign financial or other benefit values to levels of reliability.

Life Cycle Cost

Life cycle cost (LCC) are all costs associated with the acquisition and ownership of a system over its full life. The usual figure of merit is net present value (NPV). Projects are considered most favorable for large positive NPVs. However for many cost individual cases, decisions are made for the least negative NPVs. In all cases, the default position for accounting is to know the NPV for making no change and this is usually the last alternative for most people associated with change.

Life Units

A measure of use duration applicable to an item. For example, the life units may be starts-stops, run hours, hot-cold cycles, distances traveled, emergency starts or starts, shelf life, and other measurements which motivate failures.

©2012 Reliabilityweb.com