Your Reliability Engineering Professional Development Site
Find all articles across all article series listed in reverse chronological order.
The formal definition of reliability is …
“The probability that an item will perform its intended function under stated conditions, for either a specified interval or over its useful life.”
The three key terms in this statement are
Extended bogy testing builds on test to bogy (TTB), discussed in a prior article. TTB focused on calculating the number (N) of parts tested to one life bogy, with 0 failures allowed, to a specified reliability (R) and confidence (C) levels.
Using TTB to verify conformance to high reliability and confidence targets requires very large sample sizes, increasing testing cost. The capacity to test large samples may require large facility capital expenditures. Also, the zero failures allowed paradigm removes the opportunity to learn about product failure modes and the opportunity to improve the product through design or manufacturing process changes.
This article focuses on extended bogy test plans as an alternative to TTB.
Imagine you are not feeling well and you go to a doctor. When you sit down in the doctor’s office, he doesn’t even look at you. Instead, he has a book opened on the desk and starts reading it aloud. You sit there without being examined, listening to a list of medicines, activities, exercises and diet changes. The doctor then looks up and says that you need to do all of them. Take all the medicines. Change all your activities. Start doing all the exercises. And completely change your diet. [Read more…]
Design of Experiments classes always talk about Resolution III and higher designs. But what is a Resolution II design? We show what it is – and show that it is actually used quite a bit! Should be used with caution as it does not provide understanding.
www.PerrysSolutions.com [Read more…]
All stakeholders have different perspectives, and as a result, place value on different aspects of an asset. Trying to balance all the requirements is not an easy task. Whether the requirements are performance, cost, or the level of risk. Keep in mind, that performance can not only be uptime or OEE, but the beauty of a park, or the condition of a road. This is where asset management comes in. [Read more…]
You’ve started a new project; or joined one that’s up and running or it’s nearing closure – and it’s going well. With no problems to speak of, it’s business as usual; so stick to the plan and it will be all right in the end ‘cos nothing can go wrong.
Or perhaps there are problems; but all projects have problems! It’s not your problem as the bid team, planning team, or those awkward stakeholders and ever present over demanding clients can be blamed.
The project will eventually get finished if it’s on, or off, the rails. The project is ‘just a job’ and management just carry on clocking-in and clocking-out regardless of the situation. [Read more…]
Is your scrubbing tower working? A wet scrubbing tower is used to clean odors, particles, mists and vapours from a gas stream. The gas is forced through the tower. As it moves from inlet to outlet it is washed and cleaned. The washing is done with suitable chemicals that remove the active components in the gas flow. The gas is cleaned to environmentally acceptable levels and discharged to atmosphere. Keywords: packed tower, packing, fill, mist eliminator. [Read more…]
For the majority of organizations, long-term success is tied directly to the new product development process. Tomorrow’s revenue and growth are tightly bound to how successful you are at launching new products.
…fewer design iterations to achieve the same goals (reduced time to market), more efficient production and delivery processes (reduced operating costs), fewer defects & warranty costs during the entire product life cycle (increased customer satisfaction).
In the late 1970s, Hewlett Packard was a company that valued quality compliance, certification and awards. But the then Chief Executive Officer noticed a problem. He (on a hunch) initiated an analysis of ‘quality related expenses.’ He wanted to quantify the cost of defects and failure. The results were terrifying. [Read more…]
In this article, we’ll compare and contrast the definition of a requirement, with a ‘story’, which is used in agile/scrum.
The framework for each is somewhat different, however.
Recall the definition of a requirement:
…a requirement defines “what the product (or process) design shall provide <output> at operating conditions <input>”
The framework of a story is as follows:
I have always believed that the equipment that makes your products and the operators who operate it are the most valuable assets you have. From the Janitorial Serves to the CEO, unless you are manufacturing product and putting it out the door, you are overhead – just another additional cost that must be included in the cost of our product. [Read more…]
Innovative situations require strategic testing to reduce risk. The points reviewed summarize our approach when we have performed this activity. It ends up being the heart of the development plan. [Read more…]
Ask almost any maintenance professional in your operation what they think about ethics. Chances are the answers will not have anything to do with their job and their role in maintaining equipment.
Ethics play an important role in many professions, such as doctors, engineers, lawyers, etc. Ethics are not typically thought of in maintenance, but in reality, ethics does have a place in maintenance.
To understand where ethics fit into maintenance, you first have to understand ethics. [Read more…]
The 2012 Moving Ahead for Progress in the 21st Century Transportation Act (MAP 21) requires state departments of transportation to develop a Transportation Asset Management Plan (TAMP). The TAMP is to include a Risk Based Asset Management Plan (RBAMP). The two plans must be certified by the Federal Highway Administration (FHWA) by June 30, 2019. Certification failure will result in National Highway Performance Program funds being reduced by thirty-five percent. As a carrot, federal funds can be used to cover the cost of developing these plans. This article discusses the FHWA’s approach to risk management. It also shows that the FHWA approach will filter down to local governments. [Read more…]
Flow meters – don’t believe what they tell you. A flow meter is an instrument that measures the amount of fluid (liquid or gas) that passes through it. The meter in the pipe is the detecting device and increases the count when a specific quantity of fluid passes by. There are several types of flow meters in common use. They include magnetic flow meters, vortex flow meters, mass flow meters, turbine flow meters, rotor blade meters, paddle flow meters, and ultrasonic flow meters. Usual the quoted accuracy on the flow meter specification sheet is for water at 20oC. However when the meter is installed in a process application it is unlikely that the meter will meet the quoted accuracy without site-specific calibration. Keywords: calibration, certified test equipment, flow meter accuracy.
The manufacturer performs laboratory trials of its equipment to insure the flow meter meets their claims for accuracy. Since the manufacturer does not know where their meter will be used they standardise the tests by using water at known conditions. Unless the meter is used in a situation identical to the laboratory conditions the given accuracy is unlikely to be achieved. [Read more…]
