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Articles: Reliability Engineering

10 Things You Can Do Right Now To Improve Reliability

Publishers Note: We recently challenged our good friend and maintenance expert Ricky Smith to tell us 10 things we can do today - not 10 things we can buy today - to improve reliability at our plants. No new software, no new hardware, no new consultants. Ricky did as Ricky usually does and showed up with goods!

We admit he did include one “buy recommendation” but we let it pass because it falls under US$100. Here is what he came back with. - Terrence O’Hanlon, CMRP

5 Minute Audio Tip - Rules of Thumb for Maintenance and Reliability Engineers

Ricky Smith, CMRP explains Rules of Thumb for Maintenance and Reliability Engineers

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.

‘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.

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.

Blast Off to Reliability

The RCM Process at United Space Alliance

by Catherine C. Kammerer

United Space Alliance, LLC (USA) is the Space Processing Operations Contractor (SPOC) for NASA at Kennedy Space Center (KSC), Marshall Space Flight Center (MSFC), and Johnson Space Center (JSC).   In that role, United Space Alliance uses Reliability-Centered Maintenance (RCM) to optimize maintenance practices for the upkeep of tens of thousands of pieces of critical ground support, launch, and flight control equipment.  USA has an institutionalized RCM process with a company policy, functional organization procedures, periodic review of performance, and metrics to track the performance.

Block Diagram Models

Reliability block diagram (RBD) models are graphical representations of a calculation methodology for reliability systems.

Building Steam

A Story of Hard Work, Dedication, and, Ultimately, Transformation

by  Judith Charlton and Steve Lipscombe

Sembcorp UK, one of the leading suppliers of utilities to UK industry, is transforming its operations.  Steam and power operations are vital to the success of Sembcorp UK and its customers in the petrochemical, power and biofuels sectors.  Just five years ago the business was struggling to manage an aging power station and all its associated problems with limited resources.  The challenges seemed insurmountable.

Capability

A measure of how well the product performance meets objectives. In short how well are the outputs actually accomplished against a standard? Capability is frequently the product of efficiency * utilization.

Configuration Control

Configuration control is involved with the management of change by providing traceability of failures back into the design standard. If the design details are not specified, the design will not contain the requirements and thus implementation of the project will be hit or miss for achieving the desired end results beginning with the conceptual design and resulting in the operating facility.

Contracting For Reliability

Say what you want and want what you say to your vendors. Provide explanations of the objectives in contracts in terms the vendors will understand.

Corrective Maintenance Task Generation

Maintenance cost or maintenance loss? Maintenance in today's plant is a dynamic function of the ability to adapt to quick changes and to new policies and management techniques. An inherent problem common to many maintenance programs is that manpower is one of the first things considered when cost reduction is sought. The loss of manpower poses continuous challenges to any maintenance manager who is striving for world class status. Corrective maintenance experience is one of the critical areas of expertise that is often lost.

Cost Of Unreliability

The cost of unreliability is a big picture view of system failure costs, described in annual terms, for a manufacturing plant as if the key elements were reduced to a series block diagram for simplicity. It looks at the production system and reduces the complexity to a simple series system where failure of a single item/equipment/system/processing-complex causes the loss of productive output along with the total cost incurred for the failure. If the system IS sold out, then the cost of unreliability must include all appropriate business costs such as lost gross margin plus repair costs, scrap incurred, etc. If the system is NOT sold out, and make-up time is available in the financial year, then lost gross margin for the failure cannot be counted. The cost of unreliability is a management concern connected to management's two favorite metrics: time and money.

Critical Items List

The critical items list is a top level summary of problems/cost used for discussions with management about key reliability issues. The summary list converts technical details to a summary of costs and time while placing the issues into a Pareto distribution explained in terms of money and the vital few problems to be solved for competitive reasons.

Data

Data is the informational energy which runs the reliability improvement machine. Data is acquired at great cost. Data needs to be retained and used to prevent future failure events. Proper use of data provides an understanding of failure mechanisms and prevents reoccurrence of bad events which cause safety or high cost failures to occur. Reliability data requires definition of a failure. Failures can be catastrophic failures or slow degradation-you decide by defining the failures. The units of the measure for the data must be in units of the degradation-sometimes it is hours, some times it is miles, and so forth-in short, what ever motivates the failure. Reliability always ceases with a failure or a removal from service in some aged condition which then generates a category of data called a suspension or censored data. Data is information in the form of facts, figures, or engineering databases which is obtained from engineering tests, experiments, or actual operating conditions. Reliability data is often incomplete as the exact times to failure are rarely known or recorded with much precision so that only partial information is available for analysis. Reliability data comes in two forms: 1) age-to-failure data, and 2) censored/suspended data such as occurs when unfailed items are removed from service or when they fail due to a different failure mode than we are studying-this is useful information and part of the data set. Some data is better than no data for resolving reliability issues.

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