Your Reliability Engineering Professional Development Site
Establishing a reliability goal for a project is often done early.
You may already know the reliability goal guides the entire development and supply chain team.
Yet, what is the actual value of setting a reliability goal?
As seen in the previous articles, you can easily use the data you already have to conduct a meaningful analysis. This includes Weibull, Crow-AMSAA or a Mean Cumulative Function analysis.
Digging into a well manage dataset promises to reveal insights, trends, and patterns that will help improve the line, process, or plant.
Creating a plot or calculating summaries is pretty easy with today’s tools. Yet, are you doing the right analysis or are the various assumptions valid?
One critical step in the data analysis process is making sure you are doing a valid and appropriate analysis. [Read more…]
The definition of reliability includes four elements.
One of them is the intended environment where the device or system will experience a range of stresses.
The knowledge of where and how an item will operate enables:
A Petri net graph is a depiction of a system using a symbolic language.
The modeling permits the analysis of complex systems or networks of systems.
It is possible to include elements of the system that are neither function or failed. In other words, it permits modeling a system when one or more of the elements are in a degraded state or under repair.
Petri net modeling is useful when the repair/restore times are long compared to operating times, as reliability block diagrams and fault tree analysis approach assume short or insignificant repair times, in most cases. [Read more…]
Beyond the part reliability specification, you may also add conditions or requests to your reliability specification for your supplier.
The communication with your supplier should include sufficient information that they fully understand your reliability performance expectations. When buying or contracting with a supplier, you are the customer.
Be clear about your reliability requirements including constraints and conditions. [Read more…]
The best time is at the product conception. The second best time as early as possible in the product development process.
It may change. Be refined. Altered later.
That is fine, yet the initial concept needs the boundary condition of a reliability goal. [Read more…]
Unless you are working with raw materials directly, you rely on your suppliers to provide reliable parts.
Do you suppliers know your reliability objectives for the parts they supply?
If you didn’t tell them, they probably do not know. If you did tell them, did you make it the reliability specification clear and understandable?
As with any specification, clear communication is essential. Guessing or assuming both parties know and have the same reliability goals is, well, not a good practice. The ability of a supplier to build and deliver the parts that meet all your specification has to include a clear and understandable reliability specification.
There is a range of common reliability specifications in use, some are better than others. Let’s start with a brief review of reliability specification types.
Then briefly outline how you establish the reliability specifications for each supplied component. [Read more…]
Your facility has data and maybe too much data. Using simple plotting may be the key to unlocking how well your maintenance program is performing.
Building on the concept of reliability growth modeling James Kovacevic described a convenient way to quickly visualize your repairable system failure data is with a mean cumulative function (MCF) plot. [Read more…]
We make decisions all the time. Often our decision making is with little more than a gut feeling.
When faced with a major decision we often look data to help us decide. Is the product reliable enough as designed? Which field returns indicate we should stop production?
Some decision may help us earn or lose thousands if not millions of dollars.
Deciding to delay a product launch by six months means we have no revenue for the duration. The delay may also permit us to address a design flaw that would cause half the products to fail within a few months.
The later may cause loss of market share, erosion of brand loyalty, not to mention the cost of warranty claims. [Read more…]
Even products with relatively quick design cycles and short stays in the market deal with part obsolescence.
Long design periods along with long durations in service or in production simply increases the chance that one or more parts will become obsolete.
Designing systems with part obsolescence in mind helps. Working with suppliers to select parts with many sources, with long-term plans to produce, and with long term commitments, all may help. Even then, companies change priorities, go out of business, or simply discontinue the part you need. [Read more…]
Let’s discuss sources of variation and how to measure, monitor, and control processes to minimize the differences from one part to the next.
Statistical process control (SPC) is a set of tools that provide insights into the changing nature of processes.
The Department of Energy (DOE) Office of Energy conducted an Energy Storage Reliability Workshop this week provide a unique glimpse at how the stakeholders across an industry view reliability.
The representatives from government and private sector, including national labs, large and small companies, insurers and consultants gather to talk about the reliability of large-scale stationary energy storage systems.
Specifically, the focus of the workshop was on helping the DOE identify the specific activities and focus for their involvement in this relatively new industry segment.
[Read more…]
Every failure is part of a puzzle. The equipment we are maintaining is trying to communicate with the use of each and every failure.
Often the message is not obvious.
There is the immediate failure. And, if we’re paying attention we can sort out the root cause of the failure along with replacing or repairing the damaged parts. Sometimes though the damage is caused by another issue with the system. [Read more…]
One aspect of creating a new product or system is the sourcing of parts, components, and materials.
Gone are the days of your organization providing every element of the final product. Henry Ford’s supply chain for early Ford automobiles includes their own forests, rubber plantations, and iron ore mines. [Gelderman, 1981]
We increasingly rely on the supply chain to create the necessary parts for the design’s functionality. Then to continue to supply those same parts for decades, in some cases. [Read more…]
