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Fred
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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 simple increases the chance that one or more parts will become obsolete. Continue reading
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 include their own forests, rubber plantations, and iron ore mines. [Gelderman, 1981]
We increasing 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. Continue reading
Note: I’m moving this blog to Accendo Reliability under the articles menu. This series of articles or short tutorials will continue to have a unique mailing list. This series addresses many fundamental concepts and tasks for reliability professionals and will support the wider range of articles, webinars, podcasts, and courses found on Accendo Reliability.
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Software elements of a product or system take time to create. Thus re-using blocks of code developed for previous applications may save on development time. Continue reading
Physical products are made up of materials. The materials including metals, polymers, adhesives, and many others experience loads and stresses during assembly, transport, storage, and use. Selecting the right materials such that they both meet the needs of the customer and are sufficiently reliability relies on understanding how the material will respond to the applied stresses over time. Continue reading
A product or system may fail for many different reasons. One cause is a faulty part. A component is susceptible to failure when either improperly used in the design or is a damaged or flawed component.
When products were crafted one at a time, the design and manufacturing process were often done by the same person. The craftsman would design and build a chest of drawers or carriage.
Some trades would employ apprentices to learn the craft, which included design. Larger project may include an architect or lead designer along with a team of engineers. Yet the shop or site for the railroad engineer or bridge was not far allowing close communication between the ironsmith and design team. Continue reading
I’ve often said, “reliability occurs at the point of decision.”
At the point of design during the design process. At each and every decision.
The design team of engineers establish the bulk of the reliability capability early in the design process. The teams decisions about materials or shape, concerning inventions or outsourcing, about how and where to build the product, and many more decision impact the final product’s reliability performance. Reliability is designed into the product right from the start.
As a reliability engineer, you cannot be present nor discuss every decision during the design process. You cannot highlight the merits of each decision often carried out alone by the designer. You can understand the designer’s process and work to influence the myriad of decisions. You can create guidelines and information that design teams can use to inform their decisions.
Nigel Cross in Engineering Design Methods: Strategies for Product Design
This is different than how a scientist or reliability engineer would approach a problem. See Understanding the Design Process for more information on the differences in problem solving approaches. Here we need to be aware that during a design process if the decisions made along the way include a well formed set of boundaries concerning product reliability, the decision are more likely to create a solutions that will meet the reliability objectives.
Michael Joseph French is his book, Conceptual Design for Engineers
The process starts with the recognition of a need
The initial analysis is a refinement of the need and an important step in the overall process
The statement of the problem should include three elements: a formal statement of the problem (goal), limitations for the solution (constraints), and excellence criterion (criteria).
The conceptual design stage pushes designers to create solutions in the form of schemes. In this phase the designer makes the most important decisions concerning the solution and it’s eventual reliability performance. The designer balances engineering science and knowledge, production methods, and business requirements to form potential solutions.
The crafted schemes on the first iteration may be little more then concept sketches. With iteration of the evaluation steps the schemes become refined and one scheme eventually becomes the path a new product.
The embodiment stage includes greater detail for the various proposed solutions, plus an eventual selection of a scheme to craft the product upon. The results of this stage is a set of general arrangement drawings or a draft product requirements document.
Detailing as the name implies is the detailed design and engineering work to finalize the essential remaining points of the design. For the reliability engineer this is the step where design engineers make decisions concerning production methods and specifications, both impacting process capability.
The result of the design process is a set of instructions, drawings, schematics, etc., that permit the assembly and delivery of the product to fill the customer’s need.
The primary work is done by design engineers with the aide of many within the organization. The initial steps to define the problem include the questions concerning product operating environment and expected longevity. As the schemes take shape, the initial reliability evaluations influence the refinement of the reliability goals and constraints. During the final steps the reliability engineer works closely with the design team to identify and resolve potential/actual reliability issues with the design, supplied components, and production process.
Let’s start by understanding the difference between engineers and engineering designer. The work we do as reliability engineers may require a different approach when working with these different types of engineers. Continue reading
The ability to assembly a system to meet the functional requirements is constrained by the design, the materials, and the tolerances. Some designs are impossible to assembly. While other designs take little effort to build. The discipline of design for assembly, DFA, applied during the design process can enhance the manufacturing process. Continue reading
CRE preparation notes