Failure and Repair Issues

NASA: Failure Environment Analysis Tool - FEAT Technical Paper - FEAT is a software application that uses directed graphs or, digraphs, to analyze failure paths and failure event propagation.  Digraph Data System (DDS) Release 1.0. 

• Reachability
• Shuttle Integrated Risk Assessment Project 
• Logistic Analysis

Risk Solutions Inc.: Risk Management -

• The service aims to assist clients in verifying that their critical process control and safety systems are being addressed to ensure year 2000 compliance, thereby allowing them to focus their resources on remediation and/or mitigation efforts where they will be most cost effective. Also, in many cases the risk based approach can avoid the testing and shutdowns required by other techniques. Too late to fix everything? Risk assessment can also be a great help in carrying out triage for complex industrial installations.
• Examples of Y2K initiated shutdowns and malfunctions which have been identified include: PLCs locking up due to a year field overflowing, a gas pipeline fiscal metering system which simply will not work after 1999, a historical log function in a SCADA system recording corrupted entries then terminating and a large electrical generator’s stator cooling water temperature instruments shutting down the equipment on a false high temperature reading.
• The third failure mode type; aberrant input, output or action, may cause the control system to behave in a way which has not been addressed during the control system design. A Y2K initiated aberrant event may be an unrevealed failure, in the sense that the control system may not detect the failure of an instrument loop and may carry on operating the plant as normal. Hence a Y2K initiated aberrant failure in the control system may lead to more significant safety and environmental problems in the event that the process being controlled is forced or permitted to behave outside its design envelope. Potentially hazardous scenarios can be extrapolated from Y2K initiated events such as failure to react to gas detection, opening or closing valves at inappropriate pressures or levels, inadvertent hazardous mixing, over or under pressure of pipes or vessels, inability to start pumps or compressors, etc.
• The risk analysis is based on plant layout, process and instrument drawings, cause and effect diagrams and site surveys.
• The risk assessment techniques used are both qualitative and quantitative, and include mathematical modelling, HAZID/HAZOP, Fault Tree Analysis (FTA) and Failure Mode Effect Analysis (FMEA).
• The weighted risk cost can be thought of as an expected value of a failure and can be used in cost benefit analysis to determine the such important issues as the allowable investment in Y2K mitigation or remediation and the appropriate level of Y2K insurance coverage to be sought for the facility.

Stone & Webster Management Consultants

• Year 2000 embedded system vulnerability exists when equipment utilizes computer chips that read or calculate the date based on only the last two digits. Vulnerable systems include distributed control systems, programmable logic controllers, digital recorders, control stations, recorders, meters, meter reading and calibration software, and SCADA. PC based applications such as control and work management software within a utility may also possess Year 2000 vulnerability. Any date-dependent application, system or component may experience problems that result in complete system or station shutdown.

Embedded Consultants, LLC

Belcore Job Announcement:

• Fault Tree Analysis
• Failure Rate Predicitons

http://www.evolvehr.com/y2k.shtml - Y2K Jobs worldwide

National Information Center for Reliability Engineering

Power Quality Assurance Magazine

Reliability Magazine - Machinery Reliability, the Predictive Maintenance Industry, and Computerized Maintenance Management Systems.

Tools-Reliability Analysis Modeling Program (RAMP), Sandia National Laboratories, James E. Campbell

• Originaly developed for equipment suppliers to the semiconductor industry, RAMP can be used to model virtually any piece of equipment, a process, or a piece of equipment with an integrated process. Modeling results include Mean Time Between Failure (MTBF), Mean Time To Repair (MTTR), and Availability (for repairable systems), Reliability Improvement, Component contribution to Subsystem and System Failure, Susbsystem contribution to System Failure, Uncertainty Importance (the relative importance of variability of input data for each failure mechanism), and sensitivity of System Failure Rates, Availability, and Repair Rates to the MTBF and MTTR of individual components. Component failure rates can be entered as a nominal (point) estimate or as one of nine distribution types.

ItemSoft: Reliability Availability Maintainability and Safty - engineering analysis software tools

• MilStress is a powerful reliability prediction program based on the internationally recognised method of calculating electronic equipment reliability given in MIL-HDBK-217 (published by the US Department of Defense).
• BelStress is a powerful reliability prediction program based on the internationally recognised method of calculating electronic equipment reliability given in Bellcore Standard TR-332 Issue 5, Dec 1995.
• TelStress TelStress is a powerful reliability prediction program based on the following standards: Bellcore TR-NWT-000332, RDF, HRD
• MechStress is a powerful reliability prediction program based on the internationally recognised method of calculating mechanical equipment reliability given in the NSWC Standard 94/L07 (Handbook of Reliability Prediction. Procedures for Mechanical Equipment).
• FaultTree+ graphically represent the interaction of failures and other events in the system. Basic events at the bottom of the fault tree are linked via logic symbols (known as gates) to one or more TOP events. These TOP events represent identified hazards or system failure modes for which predicted reliability or availability data is required.
• RelDraw is a powerful systems reliability analysis tool which allows reliability block diagram (reliability network) analyses to be performed in an integrated environment.

RAID - In 1987, Patterson, Gibson and Katz at the University of California Berkeley, published a paper entitled "A Case for Redundant Arrays of Inexpensive Disks (RAID)" .

NAVY: Affordable Readiness Information Center and Reliability Centered Maintenance (RCM)

• Risk Assessment and
• Mean Time Between Failure ( MTBF)
• Mean Time to Repair (MTTR)
• Life Cycle Cost (LCC) estimating models
• Maintenance Schedules
• Logistics
• Defense Acquisition Board

• Affordable Readiness Documentation
• Cost of Ownership Guidebook

• Cost of Ownership, Sensitivity Analysis, Trade off Analysis
• Visibility and Management of Operating and Support Costs (VMOSC)
• Sustained Maintenance Planning (SMT)
• Affordable Readiness Implementation Plan
  • our maintenance processes
  • the reliability of our equipment
  • the conditions under which the equipment are used
  • the primary objective of tracking and reducing costs
  • what systems and subsystems consume most of our maintenance resources.
    • current Inventory and Manpower consumers.

Copyright 1988-2012  Richard Collins, All Rights Reserved