Engineering Design Notes
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Engineering design is an iterative process that applies science and problem solving techniques to modify or create something to meet predefined objectives. The basic stages include establishing objectives and criteria, analysis, synthesis, defining manufacturing techniques, usage, maintenance, and disposal. The design process involves understanding the problem, generating alternative solutions, evaluating alternatives against requirements, deciding on solutions, and communicating results through documentation. Safety, sustainability, and strategic questions are important aspects to consider throughout the design process.
Engineering Design Notes
- 1. Engineering Design is a decision making process (often iterative or recursive) in which the sciences are applied to modify/create something to meet predefined objectives (specifications). Basic stages of the design process include establishment of objectives and criteria, analysis, synthesis, definition of actual manufacturing techniques and routes as well as the modes of usage, maintenance and disposal. Design is problem solving. One possible route to follow in the design process is for example: 1. Establish the need (realise there is a problem to be solved) 2. Plan how to solve the problem (consult others, e.g. by means of brain-storming) 3. Understand the problem by developing requirements and uncovering existing solutions to similar problems 4. Generate alternative solutions 5. Evaluate the alternatives by comparing them to the design requirements and to each other 6. Decide on acceptable solutions and produce the conceptual design 7. Communicate the results, e.g. produce layout drawings, detailed design drawings and material selection (detailed discussion of material selection is at http://www.geocities.com/ontology2008/095.htm ) 8. Produce the final technical documentation including the time schedule and costing 9. Manufacture and test prototype 10. Full scale manufacture 11. Sale and follow up the customer’s satisfaction. The following figures summarise some concepts related to design process: 1
- 2. Some aspects of the design approach can be outlined as follows: Sustainability: Ideally design should anticipate (minimise) deterioration (e.g. abrasion, corrosion) of each component to prevent the need for any further maintenance, by design-out and other actions. 2
- 3. Safety aspects: • Testing workplace isolation procedures, including safety permits and the isolation tagging system, are essential in a hazardous area and must be incorporated into the planning for testing the design prototypes. • Standard job procedures, including methods, spares used, tools, and safety procedures, should be mandatory. • All prototype tests should be preceded by a discussion of safety procedures and requirements. Proposed modifications should also have been through a hazard and operability check before they are actioned. • All contract labour engaged in the design should be subject to job quality checks and should go through a safety induction programme appropriate to the specific equipment. • All spare parts, whether new or reconditioned, should be subjected to a quality assurance programme. Useful strategic questions to be asked during the design process: WHAT: Why is it done at all? / Why is it necessary? / Why not eliminate it? WHERE: Why is it done there? / Why not change the place? / Why not change the sequence? / Why not combine? WHO: Why does the person do it? / Why not change the person? / Why not change the sequence? / Why not combine? HOW: Why is it done this way? / Why not do it a different way? / Why not improve it? / Why not make it easier? Components of the final product quality that should be aimed at are presented below: Since any design is an experiment, it is sensible to use the design technique termed “probabilistic design”, especially if we our design project involves consumption of significant resources. (See also: http://www.grassmannalgebra.info/probabilisticdesign ). 3