The Design ProcessMorphology & AnatomyApplying Technology..The Design ProcessDesign is..the essence of engineeringStarts with ...recognition of some needProgresses to physical implementationResults may be simple or complexeg. Need..to join sheets of paperResults?eg. Need..to transport people from their homes to work...Results?Design can be of two kinds....something completely new.....oran improved form of something already in existenceMorphology of DesignThe consideration of the product life from its conception to retirement.....Needs AnalysisFeasibility StudyPreliminary DesignDetailed DesignProductionDistributionConsumptionRetirementProblem DefinitionSolution SynthesisBest DecisionAnatomy of DesignDetailed examination of the engineers actions as he/she identifies and solves theproblemProblem statement and formulationInformation collectionModellingValue statementSynthesis of alternativesAnalysis and testingEvaluationDecisionOptimisationIterationCommunicationAnatomy and Morphology...They work together...Panoramic view of engineering.. TheDesignMatrixNot necessarily chronological distinct ordered steps..Continual iteration and revisionThe design matrix will identify a methodology applicable to any design from a simple component to a complex designSome parts may be trivialised.... some parts may take the majority of the effort expendedThe Design Matrix(M1) Needs AnalysisCreation begins by recognising a needeg. apparent from observationor results of a detailed studyor a specific setof circumstancesResults in a primitive statement eg . fact or opiniondoes the need exist and is it realistic?does it exist now or.. will it exist in the future ?is it a new need ? (new material or physical principle)Often depends on circumstanceseg. polluted air..mask/exhausts/noneNeeds analysis once through the Anatomy provides a good starting point for the Feasibility Study(M2) Feasibility StudyDesignscan be futile unless satisfying the original need is feasibleAt this stage, the product appears in abstract forms, but are they feasible?Alternative solutions must be subjected to physical and economic analyses and be realisable from both..The Feasibility Study using analysis of several alternatives establishes the design concept as something which can be realised and accepted...Some examples..... Primitive Needs & Qualitative Statements(i) An airport is congested.A rapid transit link is required to a nearby airport with a specified number of people in a given time, amount of baggage and freight in a given time and speed of passage.(ii) A building must be comfortable to live in.Heating, ventilation and air conditioning are required. Specify limits of temperature, humidity, velocity and fresh air constituency.(iii) National fossil fuel supplies are low.Alternative forms of energy supply are required. Specify amount and where they are needed, and any restrictions of space, time or pollution levels.New Alternatives/New Problems ?From the example overleaf (3), there are new alternatives which must be checked by aFeasibility AnalysisAlternative energy sources may be..Nuclear, solar, tidal, wind, geothermalConsider Solar Power....Is it workable as a national source??Use a solar collector is space.....How large must it be ?Can the beam always point to the same spot on earth ?Can the energy be focused into a beam of reasonable dimensions ?How large a receiving area is needed ?Would such a beam be dangerous ??Can the collector be placed in orbit ?Is it economically feasible and publicly acceptable ?Will it upset the ecological balance ?(M3/4) Preliminary Design/Detailed DesignPreliminary Designmain purpose is selection of the best possible solution froma choice of alternativesmake comparisons against given criteria & constraintsmust maintain an open mind....use your judgement!Detailed designaim is to produce a complete set of working drawings which are then transmitted to the manufacturerthis stage of design is far less flexible than those previousdesign should now reflect all of the planning both for manufacture and consumption stagesconstruction/testing of various components may be requiredprototype building ....is it what was expected ?Up to this point, a design is still provisional. Various degrees of revision may be yet necessary in order to get it right.For various reasons, the design may even be scrapped...A good design must always be prepared for such an eventuality(M5/6)Production and DistributionProduction Here, the device or system is actually constructed,and planning for thisshould have been incorporated into the designKnowledge of the capability of the machines is required, since it must be possible to build and assemble the components as specifiedSpecial jigs, fixtures and even machines may be requiredPlanning is vital..including quality control hold points, methods of inspection, standards for comparison etc...Timing of construction may be important eg. climatics...DistributionTransportation of the manufactured article, complete or in subassembly form must be anticipated in the design..Packaging, availability of vehicles, regulations for use of thoroughfares, shelf/component life, warehouse storage facilities, special handling, environmental control of temperature and humidity may need to be addressed(M7/8) Consumption and RetirementConsumptionThe product is now used by the consumerIf the design is effect, it will have met the need....The design may yet not be complete..redesigns and modifications may be required depending on field trials or consumer feedback.... (very important to find this out!)May need to consider maintenance of components and supply of spare parts or subassembliesRetirementThe product will be discarded as its life cycle terminatesIt may have become obsolete whilst still serviceable and therefore the design may not have been fully economicalDisposal and recovery of useful materials should have beenincluded in the designThreats to safety should be guarded against....Simple Tutorial (1)(1) Discarded refrigerators that have led to child suffocation(2) Failure to invent jet propulsion for aircraft at anearlier period(3) A piece of furniture that will not pass through a standard door(4) A motor which cannot be assembled(5) Throwaway beer cans(6) The modern automobile(7) Lead-based house paint(8) A bridge that uses up the available capital when only half completed(9) A product that nobody wants to buyChoose one of the following cases, (last digit of your student number) and identify which component(s) of the design matrix was neglectedSubmit one page of A4 with your name, student number, question and answers, by next Tuesday.(A1/2) Problem Statement& Information CollectionProblem StatementDefinition ofthe problem and set a clear formulation of the goalsto be achievedConstraintsand limitations are recognisedProblem statement will mature to form a complete specificationHowever, clarifications and additions may become necessary as the design proceedsInformation Collection All relevant information which may have a bearing on the problemTechnical literature, reports, text books, information retrieval, computer searchesFor example..... material properties, component and system performance,empirical data, analytical formulations, performance of existing or similar designsMay need to generate new information by tests or experimentsMuch reading required... especially ofother allied fields, eg.geography, sociology, finance...(A3) ModellingPreferable to model a system rather than to build and see.(which can be hazardous!)Various models available; Graphical Diagrammatic Mathematical Analogue IconicModels involve some simplifying assumptionsWhat effects can be assumed/neglected?Assumptions of environment (for example , uniform temperature?)Constant quantities (time, space??)Lumped physical quantities (mass etc?)Linearity ?Noise and uncertainty ?(statistics?)Graphical ModelsSimon p82Poor Graphical ModelsSimon p87Diagrammatical ModelsSimon p81More Diagrammatical ModelsSimon p61Iconic ModelsThese include photographs, maps, working drawings/sketches3D models are common eg.... scale models of aircraft for advertising, as a mockup for seat location and designfactory or building layoutpiping layouts on chemical plantAnalogue ModelsMay look like iconics but behaviour is importantModernuse is mainly in simulation eg. drive a car, land an aircraft, dock a spacestationIconic and Analogue ModelsSome Iconic Models....