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Theengineering design process, also known as theengineering method, is a common series of steps thatengineers use in creating functional products and processes. The process is highlyiterative – parts of the process often need to be repeated many times before another can be entered – though the part(s) that get iterated and the number of such cycles in any given project may vary.
It is adecision making process (often iterative) in which the engineering sciences, basic sciences and mathematics are applied to convert resources optimally to meet a stated objective. Among the fundamental elements of thedesign process are the establishment of objectives and criteria, synthesis, analysis, construction, testing and evaluation.[1]
It's important to understand that there are various framings/articulations of the engineering design process. Different terminology employed may have varying degrees of overlap, which affects what steps get stated explicitly or deemed "high level" versus subordinate in any given model. This, of course, applies as much to any particular example steps/sequences given here.
One example framing of the engineering design process delineates the following stages:research, conceptualization, feasibility assessment, establishing design requirements, preliminary design, detailed design, production planning and tool design, and production.[2] Others, noting that "different authors (in both research literature and in textbooks) define different phases of the design process with varying activities occurring within them," have suggested more simplified/generalized models – such asproblem definition,conceptual design, preliminary design, detailed design, and design communication.[3] Another summary of the process, from European engineering design literature, includesclarification of the task, conceptual design, embodiment design, detail design.[4] (NOTE: In these examples, other key aspects – such as concept evaluation and prototyping – are subsets and/or extensions of one or more of the listed steps.)
Various stages of the design process (and even earlier) can involve a significant amount of time spent on locating information andresearch.[5] Consideration should be given to the existing applicable literature, problems and successes associated with existing solutions, costs, and marketplace needs.[5]
The source of information should be relevant.Reverse engineering can be an effective technique if other solutions are available on the market.[5] Other sources of information include the Internet, locallibraries, available government documents, personal organizations,trade journals, vendor catalogs and individualexperts available.[5]
Establishing designrequirements and conductingrequirement analysis, sometimes termedproblem definition (or deemed a related activity), is one of the most important elements in the design process[6] in certain industries, and this task is often performed at the same time as a feasibility analysis. The design requirements control the design of the product or process being developed, throughout the engineering design process. These include basic things like the functions, attributes, andspecifications – determined after assessing user needs. Some design requirements include hardware and software parameters,maintainability,availability, andtestability.[2]
In some cases, afeasibility study is carried out after which schedules, resource plans and estimates for the next phase are developed. The feasibility study is an evaluation and analysis of the potential of a proposed project to support the process ofdecision making. It outlines and analyses alternatives or methods of achieving the desired outcome. The feasibility study helps to narrow the scope of the project to identify the best scenario.A feasibility report is generated following which Post Feasibility Review is performed.
The purpose of a feasibility assessment is to determine whether the engineer's project can proceed into thedesign phase. This is based on two criteria: the project needs to be based on an achievable idea, and it needs to be withincost constraints. It is important to have engineers with experience and good judgment to be involved in this portion of the feasibility study.[2]
A concept study (conceptualization,conceptual design) is often a phase of project planning that includes producing ideas and taking into account the pros and cons of implementing those ideas. This stage of a project is done to minimize the likelihood of error, manage costs,assess risks, and evaluate the potential success of the intended project. In any event, once an engineering issue or problem is defined, potential solutions must be identified. These solutions can be found by usingideation, the mental process by which ideas are generated. In fact, this step is often termedIdeation or "Concept Generation." The following are widely used techniques:[2]
Various generated ideas must then undergo aconcept evaluation step, which utilizes various tools to compare and contrast the relative strengths and weakness of possible alternatives.
The preliminary design, or high-level design includes (also calledFEED or Basic design), often bridges a gap between design conception and detailed design, particularly in cases where the level of conceptualization achieved during ideation is not sufficient for full evaluation. So in this task, the overall system configuration is defined, andschematics,diagrams, andlayouts of the project may provide early project configuration. (This notably varies a lot by field, industry, and product.) During detailed design and optimization, the parameters of the part being created will change, but the preliminary design focuses on creating the general framework to build the project on.[2]
S. Blanchard and J. Fabrycky describe it as:“The ‘whats’ initiating conceptual design produce ‘hows’ from the conceptual design evaluation effort applied to feasible conceptual design concepts. Next, the ‘hows’ are taken into preliminary design through the means of allocated requirements. There they become ‘whats’ and drive preliminary design to address ‘hows’ at this lower level.”
Following FEED is the Detailed Design (Detailed Engineering) phase, which may consist ofprocurement of materials as well.This phase further elaborates each aspect of the project/product by complete description throughsolid modeling,drawings as well asspecifications.
Computer-aided design (CAD) programs have made the detailed design phase more efficient. For example, a CAD program can provideoptimization to reduce volume without hindering a part's quality. It can also calculatestress anddisplacement using thefinite element method to determine stresses throughout the part.[7]
Theproduction planning and tool design consists of planning how tomass-produce the product and which tools should be used in themanufacturing process. Tasks to complete in this step include selecting materials, selection of the production processes, determination of the sequence of operations, and selection of tools such as jigs, fixtures, metal cutting and metal or plastics forming tools. This task also involves additionalprototype testing iterations to ensure the mass-produced version meetsqualification testing standards.[2]
Engineering is formulating a problem that can be solved through design. Science is formulating a question that can be solved through investigation. The engineering design process bears some similarity to thescientific method.[8] Both processes begin with existing knowledge, and gradually become more specific in the search forknowledge (in the case of "pure" or basic science) or asolution (in the case of "applied" science, such as engineering). The key difference between the engineering process and the scientific process is that the engineering process focuses ondesign,creativity andinnovation while the scientific process emphasizes explanation, prediction anddiscovery (observation).
Methods are being taught and developed in Universities including: