Your Reliability Engineering Professional Development Site
A listing in reverse chronological order of articles by:
In manufacturing environments, especially in high-volume production processes, it is important to ensure the highest Machine availability rate for critical equipment as a crucial factor in achieving the expected output goals. The more the availability value there is, the better the plant’s capacity to achieve production requirements since the time available for each piece of equipment will be maximized.
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Failures during product testing and use are a fact of life. Even with the most robust design we can develop an overly aggressive reliability test or find users that dish out punishing treatment, causing product failures. And for designs that are less robust, standard reliability tests and normal users will cause failures, occasionally or frequently depending on the design robustness.
When a product fails, its related to failure of individual components and/or joints between components. When a component or joint fails, it’s because their materials degraded to the point that the component or joint could no longer perform as required.
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Any product is an assembly of components comprised of different materials. The reliability of the product depends on the reliability of the materials – their ability to withstand exposure to the use conditions without degrading to the point that the component or joint stops performing as needed.
There are two approaches for evaluating the reliability of materials: 1) product testing and 2) materials testing. Both involve exposing test samples to actual or simulated use conditions and evaluating the response of the test samples as a function of the amount of exposure to the test conditions. For example, exposure to thermal cycling between -40 and +40 °C or exposure to salt spray. [Read more…]
A comprehensive reliability engineering program for a new product is a large investment. Not just in dollars, but more importantly, in time. No matter if you are a Fortune 500 company or a startup in your second year, time is always the freight train bearing down on you without mercy. I am going to give you a simple recipe I use for making a highly reliable product when that train horn is blaring and only getting closer. [Read more…]
In the previous article I discussed sources of stressors that can cause degradation of the materials in components and joints. In this article I’ll discuss the basics of metal corrosion – the electrochemical cell, seven common forms of corrosion, and examples of metals engineering and mechanical design approaches to control corrosion.
In the previous articles I discussed the component design process, the considerations for designing components, and the importance of leveraging materials engineering to design components that meet performance and reliability requirements at low cost.
I will start focusing on reliability, discussing the considerations for identifying component and joint reliability requirements. I will refer only to components for ease of writing and reading, but the discussion also applies to metallurgical joints, i.e. weld, braze, and solder joints.
In this article, I will discuss identification of the conditions that can cause degradation of the materials that comprise components and joints. [Read more…]
In the previous article I discussed product design in general and the importance of leveraging materials engineering to design components that meet performance and reliability requirements at low cost. Both component form and materials can and should be engineered to optimize a component’s design.
In this article I discuss a component design process that explicitly includes materials engineering considerations. This process involves consideration of all design requirements and cost. Not just designing for reliability. That’s where selecting materials gets tricky – having to consider different sets of requirements and design for ease of component fabrication and joining.
This article is the first in a series about material engineering and product reliability. The intent of the article is to provide you with a basic understanding of product reliability as viewed through the eyes of a material engineer. When I first talk to engineers who have a different background or focus, I start with the basics. As we speak more, I expand into relevant areas one at a time. That is what I hope to do with this series. Introduce you to some basics, and then move on to a deeper dive into the topic.
When considering product reliability, a materials engineer is concerned with how the materials in components respond when exposed to stressors that can cause the materials to degrade. Stressors include mechanical loads, corrosive environments, chemicals, heat and cold, electricity, and radiation. You may find additional stressors based on the environment components are used in, or how they are used. It’s a problem if a component or joint in a product degrades to the point where it stops functioning as required.
A plan is a road map toward a destination. It provide guidance toward a goal. The idea of a plan is to consider the path forward, the knowledge necessary to acquire, and the decisions along the way.
No plan is perfect other than those that successfully accommodate the successes and setbacks along the way. No plan can anticipate all the information yet to be uncovered, yet it can set a course to deliberately uncover what is necessary to move forward.
One of my more unfortunate memories of my early military career is the death of a soldier on a training exercise. I was posted to a place very close to the equator … along with the heat and humidity that came with it. The soldier who died suffered from heat stroke, brought on by dehydration. And when we looked back on what went wrong, a key issue was that the training exercise risk assessment was ‘word for word’ identical to previous risk assessments when it came to managing heat related illnesses.
Organizations are all about ‘success.’ Being ‘successful.’ Which can many different things to many different people. ‘Success’ is not simply the ‘antithesis of failure.’ One could argue that ‘mediocrity’ in many cases is accepted as the antithesis of ‘failure.’ ‘Mediocrity’ is hardly the same as ‘success.’
Organizational success means that a lot of different people need to be doing lots of very different, but very important things. And this often means things that can go unnoticed. The ‘one percenters.’ Getting things done right the first time.
I often start teaching my reliability engineering courses … by focusing on other reliability engineering courses. Why? Because they exemplify what is wrong with how most ‘reliability experts’ go about convincing others to take reliability seriously.
A typical reliability engineering course will start with images of disaster. A Chernobyl here. A Fukushima there. A crashed airplane. The Tacoma Narrows Bridge. Lots of other atrocities that happen when we don’t do reliability engineering properly.
I (like most of us) try to keep learning about stuff. And this includes (on occasion) listening to guys like Simon Sinek who has made a name for himself as an inspirational speaker and author. I learn a lot from some of his stuff. Most people like Simon are skilled at simplifying fundamentally ‘good’ ideas and principles into really simple messages that are easy to break through our sometimes cluttered brains.
We’ve all been ‘there.’ Watching the ‘mechanical’ design team lead go through 378 PowerPoint slides of suffocating technical content, pixelated iPhone pictures of bearing housings, and lists of ‘open’ items in fonts that are too small. There are ‘senior’ engineers wheeled in to ‘review’ but instead nod knowingly and ask sporadic questions about something they once designed ‘back in the day.’ And the chairperson will often ask our ‘mechanical’ design team lead if they are ‘on track.’
At the 2019 Annual Reliability and Maintainability Symposium, I was involved in a discussion with US Department of Defense (DoD) reliability engineering teams and industry representatives. And on the agenda was a review of an emerging document called the ‘Reliability and Maintainability Engineering Management Body of Knowledge.’ Let’s call this the ‘DoD RAM BOK’ for short.
I only had access to this document’s quick reference guide, and it suggests that the DoD RAM BOK describes what reliability engineering activities need to happen from ‘concept’ through to ‘operations’ for a typical military capability being introduced into service.
