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Availability

A tool for measuring the % of time an item or system is in a state of readiness where it is operable and can be committed to use when call upon.  Availability ceases because of a downing event which causes the item/system to become unavailable to initiate a mission when called upon.  In the simplest view the metric is availability = uptime/(uptime + downtime).  For many other definitions see MIL-HDBK-338, section 5.

“Busted” - The SAP EAM/PM Maintenance Myth

Stephen J. Thomas

There are those that believe that SAP EAM/PM is a software application that does not provide satisfactory support for the maintenance and reliability work processes that exist within the plant environment. The recent survey of over 700 maintenance managers and reliability professionals conducted by Reliabilityweb.com dispels this belief entirely! In fact 66% of the respondents actually rated SAP EAM/PM as a good to excellent tool for the execution of maintenance activities.

‘Big M’ and the Performance Culture

Managing Maintenance for Production Reliability

by James Davis, PE, CMRP

About 30 years ago, the Plant Engineer of an ITT Rayonier paper mill in north Florida called me into his office and announced that, as a reward for a job well done, I was being given the position of Plant Maintenance Engineer.  This was a bit confusing at first, as I was a mechanical/civil Project Engineer at the time, in a 38 year old facility that had never had a Maintenance Engineer.

Back to the Basics - Delivering a Maintenance Plan

by Malcolm Hide

So how do you go about setting up all of the maintenance requirements for several thousand discretely maintainable assets? This was the challenge facing us when we needed to set up the maintenance requirements package for a baggage handling system in a new airport terminal in a major international airport. From previous experience, and the airport requirements, we had a good idea of what needed to be done. The challenge was in the sheer size of the system-with a total asset base of over 28,000 discretely maintainable assets, we needed to find a more efficient way of doing things. As a result, we developed a three-step process (see Figure 1) that delivers a robust maintenance plan, based on a clearly defined strategy, which is easy to review and enables the implementation of changes when necessary. We have found that the principles hold well, regardless of the size of the system.

Back to the Basics - Developing and Delivering a Maintenance Plan

By Malcolm Hide

So how do you go about setting up all of the maintenance requirements for several thousand discretely maintainable assets? This was the challenge facing us when we needed to set up the maintenance requirements package for a baggage handling system in a new airport terminal in a major international airport. From previous experience, and the airport requirements, we had a good idea of what needed to be done.

Backlog Management

Fundamentals of Maintenance Planning Series

By Daryl Mather

Few tools are as useful to managing the maintenance workload and effectiveness as the Maintenance Backlog. In many companies today management of the maintenance backlog has been neglected. As a result they are generally drowning in their own data. A poorly managed system has a dramatic effect on the entire delivery of maintenance services.

 

Balancing a Generator at a Hydro Electric Plant

Just two years after installation of a new turbine-generating unit at the 93-MW Thompson Falls hydro project, PPL Montana LLC noticed increasing vibration values on the generator guide bearing. After several unsuccessful attempts to correct the problem, plant personnel adjusted the clearance on the guide bearings. Since that work was completed, the unit has operated within acceptable vibration values.

Balancing of an FD Fan at a Refinery

Presented by Troy Feese

There are several commercially available software packages, such as SMS Star and ME'Scope, that can be used to perform operating deflection shape (ODS) measurements.

This article provides a case history of a forced draft (FD) fan that experienced high vibration due to unbalance and an impeller resonance near the operating speed. The common balancing method of influence coefficients was unsuccessful due to varying phase data. However, vibration was reduced to an acceptable level using the four-run method without phase data.

Balancing Out the Root Cause

As anyone who has practiced vibration analysis knows, vibration signatures obtained on routes are often far from the wall chart examples. The reason for this is that the vibration signatures collected and analyzed represent the response of a system due to a variety of different forces that act simultaneously to produce one signature. Unfortunately, vibration analysts are actually interested in determining the individual forces that cause the response. Once the forces are accurately identified, only then can they be reduced or eliminated.

By Chad Wilcox

Balancing Weights: Radius Changes & Splitting

By Dennis Shreve

Oftentimes in real-world balancing applications, you will come across a way to get a quick measurement and make and verify an unbalance correction via a temporary solution with clamp-on weights or some type of balancing compound (like modeling clay or bee's wax).

Balancing Without Phase

Dennis Shreve, CMRP

Sometimes it may be required to balance a rotating machine or part under conditions where a conventional phase measurement is either impossible or unavailable. In this situation, a four-run method can be used to arrive at an amount and position for a corrective weight.

Bathtub Curves

The concept is derived from the human life experience involving infant mortality, chance failures, plus a wear out period of life since data for births and deaths is accumulated by government agencies. Most equipment lacks the birth/death recording by government agencies and most non-human systems can be regenerated to live/die many times before relegation to the scrap heap.

Belt Faults

Belt drives can cause many strange looking spectra. To analyze and troubleshoot belt drives it is imperative to have a high resolution analyzer. I use one with 3200 lines of FFT. To those still using 400 lines that might seem like overkill. This paper, though, will show the necessity of high resolution when troubleshooting many vibration problems.

Benchmarking a Better Understanding

Benchmarks Shed Light on Maintenance & Reliability Perceptions

by Klaus M. Blache, PhD

This interesting study compares data collected in 2008 to data collected in 1991 to chart the trends in reliability and maintenance over the last 17 years.

Benefits of the Planned Domain

By Winston P. Ledet
The Manufacturing Game

We have spent considerable time in the Manufacturing Game newsletter focusing on the benefits and execution of the precision domain - removing the defects at the source (Figure 1). Our philosophy has evolved based on working with clients and modeling reliability; most organizations would be advised to focus first on eliminating defects and then on making the defect removal process more efficient with a planning and scheduling process. However, there are significant benefits to the Planned Domain and this article focuses on the specific benefits that are generated through the Planned domain and the keys to a successful transition to the planned domain. Using our Dynamic Benchmarking model and data from a hypothetical chemical plant we modeled at DuPont we were able to calculate the benefits.

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