공학입문설계 설계과정 설계과정 문제정의 관련자료수집 다양한해결책제시 해결책평가및선택 설계구현및시험 1
설계개념 발명 혁신 ( 혹은개선 ) 설계는정답이없는 open solution을찾는것 (answer vs solution) 설계과정 5단계설계과정 문제정의 : user /system requirements 관련정보수집 : system s functional specifications, identification of design 다수의해결책제시 (generation of solutions showing details of design based on design constraints cost, safety, technology, user, etc) 해결책책평가및선택 (selection of one solution based on evaluation criteria) 설계구현및시험 (design implementation and testing) 2
기술설계과정 공학설계과정 1. 단계 : 문제정의 Identify and establish the need ( 필요성확인과설정 ) Develop a problem statement ( 문제서술개발 ) Establish criteria for success ( 성공을위한기준설정 ) The design must be low cost ( 가격경제성 ). The design should be safe, particularly with small children( 안전성 ). The design should not be detrimental to the environment( 환경 ). The design should be aesthetically pleasing( 미학성 ). The design should ldbe simple to operate, with ihminimum i human effort( 편리성 ). The design must be disposable (you don't reuse the trap). The design should not cause undue pain and suffering for the mouse( 사회성 ). 3
2 단계 : 관련정보수집 Search for Information Resources Wikipedia( 위키피디어 ) 백과사전 handbook ( 핸드북 ) electroncic catalog( 카달로그 ) 인터넷주제검색 expertise s advice( 전문가의견 ) 3 단계 : 다수의해결책제시 (1/) Characteristics for Creative Thinking( 창의적사고의특성 ) Curiosity and tolerance of the unknown Openness to new experiences Willingness to take risks Ability to observe details and see the "whole picture. No fear of problems. Ability to concentrate and focus on the problem until it's solved 4
3 단계 : 다수의해결책제시 (2/) Brainstorming 기법 스캠퍼 (Scamper) 기법 브레인스토밍 1. 브레인스토밍의 4가지규칙 1 가능한많은아이디어를만들어라 아이디어의질보다개수가많은것이더중요 2 엉뚱한아이디어가환영받는다 엉뚱한아이디어일수록창의적인아이디어로가는시발점 3 편승 ( 히치하이킹 ) 이장려된다 다른사람의아이디어를발전시켜서자신의아이디어를만들어라. 4 비판은불허한다 판단은나중으로미룬다. 절대로남의아이디어를비판해서는안된다. 5
브레인스토밍 절차설명 1 아이디어창출 모든아이디어에번호부여 ( 편승아이디어도새아이디어로간주 ) 팀원이많을경우순번대로발언 ( 잊어버리지않게메모 ) 2 아이디어쓰기 카드마다하나의아이디어를기록 ( 글 or 스케치 ) 하여책상위에나열 또는화이트보드에아이디어기록하고회의후카드에기록하여보관 3 시간제한 시간제한 (20~30분) 을주고아이디어할당량부여 브레인스토밍 브레인스토밍의수행 브레인스토밍시작 잘알려진아이디어를먼저제안하여마음속에서삭제 ( 짐버리기 (load dumping)) 신선한아이디어창출 아이디어창출이부진하면진행자가황당한아이디어를제시, 또는 만약 ~ 한다면 이라는질문을던져봄 계속부진하면잠시휴식을취하고억지끼워맞춤방법 (SCAMPER) 을사용 40~50개정도의아이디어창출유도 6
스캠퍼법 1. 스캠퍼법이란? 창의적인아이디어도출에박차를가할수있는방법 1953년 Alex Osborn이처음제안되고 Robert Eberle에의해발전된체계적인아이디어창출법 변형또는조작등을통하여다각적인사고를전개함으로써효과적으로아이디어를생산하는방법 [Checklist법] Substitute( 대체 ), Combine( 결합 ), Adopt( 적용 ), Modify & Magnify( 변형및확대 ), Put to other use( 용도변경 ), Eliminate & Minify( 삭제및최소화 ), Reverse & Rearrange( 방향전환및재배열 ) 의두 ( 頭 ) 문자합성어 스캠퍼법 7
스캠퍼법 스캠퍼법의적용 (1) 스캠퍼법의진행방법 1 문제나주제가무엇인지파악 2 이로부터어떤새로운아이디어가나올수있는지스캠퍼목록에맞추어검토 3가능한한모든idea를떠올린후창의적인생각을표현 (2) 스캠퍼법의장점 주어진질문의패턴에따라사고를전개시키므로초보자도쉽게활용 문제인식의습관화가능 주변의불편한점 스캠퍼 인류의생활을편하게할수있는제품발명 아이디어와솔루션정리 새로운아이디어 / 솔루션을얻는과정 1 st step: 아이디어창출 ( 엉뚱하고무모한아이디어포함 ) ~ 발산적사고필요 ( 브레인스토밍 ) 2 nd step: 아이디어정리 ( 정의 : 주어진문제를풀어나가기위하여첫번째단계에서창출된아이디어를좀더우수하고실용적인개념으로승화시키는과정 ) ~ 수렴적사고필요 8
아이디어 / 솔루션정리 그림 5.3 아이디어정리과정 4 단계 : 해결책평가및선택 (1/) Analysis of Design Solutions( 설계해결책분석 ) Functional analysis( 기능적분석 ) Industrial design/ergonomics( 산업적 / 인간공학적분석 ) Mechanical/Strength analysis( 기계적 / 강도분석 ) Electrical/Electromagnetic( 전기적 / 저자파적분석 ) Manufacturability/Testability( 제작성 / 시험성분석 ) Product safety and liability( 제품안전성과책임성분석 ) Economic and market analysis( 경제성과마케팅분석 ) Regulatory and Compliance( 규제및기준, 표준적합성분석 ) 9
4 단계 : 해결책평가및선택기준 (2/) The Decision Process( 의사결정과정 ) creating a decision matrix( 중요도, 원하는속성, 설계기준에따른 ): These attributes can include factors such as safety, manufacturing considerations, the ease of fabrication and assembly, cost, portability, compliance with government regulations, etc. Evaluating each design alternative against the stated criteria Use of computer modeling and prototypes Example: Aluminum Can Crusher Students are being asked to design a simple device to crush aluminum cans. A student design team proposes four solutions to the problem. They develop six criteria that are important to a successful design. The student team agrees that the most important criteria (or desirable attributes) of the design and assigned weights are Safety: 30 percent (30 points) Ease of use: 20 percent (20 points) Portability: 20 percent (20 points) Durability and strength:10 percent (10 points) Use of standard parts:10 percent (10 points) Cost:10 percent (10 points) 설계평가의중요성 설계는창안 (creativity), 분석 (analysis), 평가 (evaluation) 설창 y, y, 평라는세가지활동의반복이다. 개념설계단계에서의평가는미완의아이디어를평가한다는점에서특히중요하다. 설계의평가는각각의설계를여러가지설계기준 (design criteria) 과비교함으로써행해진다. 취합된데이터는각설계의장점과단점을결정 취합된데이터는각설계의장점과단점을결정 가장좋은설계안선정에기준을제시 설계안들의장점을통합해서새로운설계안을창출 선정된설계의단점수정에도사용 10
의사결정행렬 (Decision matrix) 각개념설계가일련의설계기준들을얼마나잘만족하는지를평가하기위해사용한다. 설계안이갖는다양한속성들을설계사양에나타난변수들과비교하여속성을수치데이터로변환한다. 검토와평가과정에하나의하부기반을제공한다. 각개념설계의특성을평가기준과체계적으로비교할수있도록접근방법을제공한다. 장단점을결정하기위한기초를제공한다. 의사결정행렬을이용한 9 단계평가 1. 평가기준의결정 2. 평가기준의중요도판단과가중치부여 3. 평가기준별변수와단위확정 4. 점수부여를위한가치함수의확정 5. 각평가대상의점수계산과의사결정행렬표작성 6. 각평가대상들의취약부파악 7. 상위점수획득평가대상들의취약부개선방안마련과추가적인해결안개발 8. 재평가 9. 평가대상들의최종순위결정 11
평가기준의중요도판단과가중치부여 만약사용되는평가기준들의중요도가모두비슷할경우 : 가중치는사용하지않음 가중치 : 개별평가기준이해결안의전체가치에미치는상대적기여도 이용가치분석에서가중치는 0에서 1 ( 또는 0에서 100) 사이의값 ( 양의실수 ) 모든평가기준들 ( 최하위단계에서의부분목표들 ) 이갖는 가중치의총합은 1 ( 또는 100) 평가기준별변수와단위확정 평가기준에알려진변수할당 : 정량화된변수또는 문장화된변수 예를들어자동차에서 연료소모량 이라는평가기준 사용되는변수 : 연료 1 리터당주행할수있는거리 ( 1 리터당주행거리 ) 사용단위 : km/l 12
평가기준과변수및단위가작성된평가표의예 각평가대상의취약부파악 특정평가기준에대한점수가지나치게낮다면좋은설계안이라고할수가없다. 예를들어자동차가아무리경제성이뛰어나고외관의디자인이우수하며편의성도좋고주행성능이뛰어나더라도제동성능이좋지가않다면사용할수없는자동차라고할수있다. 취약점를찾아내는방법 가치윤곽을그려보는것이효과적 전체의면적은총가중점수 각평가기준의끝부분을연결하여만든선이가치윤곽 가치윤곽중에왼쪽으로들어간부분이평가대상이가지는취약부 취약부가없는가치윤곽 : 균형잡힌가치윤곽 13
설계아이디어도면 This team also proposes four alternative solutions to this problem, which are illustrated in the following Figure. They are 1. A spring loaded crusher 2. A foot operated device 3. A gravity powered dead d weight crusher 4. An arm powered lever arm crusher 평가대상의최종순위결정 해결안을도출하여이들을비교평가하고, 취약부파악 개선 재평 가의과정을여러번반복 해결안이충분히개선되고더이상특별한취약부가없는가치윤곽을가지고있으며우수하다고받아들일정도의평가점수를받은평가안이존재할때까지반복 최종순위를결정 점수와의차이가크지않을때는여러개의해결안에대하여모두다음단계의설계절차를동시에진행 14
평가기준및평가표 After analyzing each solution against the six criteria, the team evaluates each design alternative. 설문조사평가 Although rating each design against the six stated criteria is subjective, the rating factor for each design alternative is assigned according to the consensus of the design team. The results of an analysis are used to evaluate and rate each design. The rating factor R( 점수비중 ) is assigned according to the following scale: Excellent( 최우수 ) 9 10 Good( 우수 ) 7 8 Fair( 보통 ) 5 6 Poor( 미흡 ) 3 4 Unsatisfactory( 불만족 ) 0 2 Design 4 was chosen the best design largely due to the rating assigned for safety, criterion l. The team felt that the chances of human injury were negligible for this design. Since safety is the most important factor (30% of the total weight), the high safety rating for design 4 gives it the highest overall score (9 x 30, or 270). 15
5 단계 : 설계구현및시험 (1/) Prototyping 동작가능한프로토타입제품제작및시험 Concurrent Engineering( 동시설계및분석진행 ) CAD 툴사용 Documentation( 문서화 ) 의사소통의한방법 Applying for Patents( 특허처리 ) 왜필요한가? A patent will not protect you from someone else copying your solution, but it does give you specific rights to make and sell your design for a specified period. 5 단계 : 설계구현및시험 (2/) Implementation,Testing, Debugging and Verification( 구현, 시험, 디버깅및검증확인 ) Testing = The process of executing software with the intent of detecting the presence of defects. Testing is only one of many verification activities. Debugging = The act of fault diagnosis and correction. Debugging concerns rework. 16
시험 What Qualities to Test Utility( 가용성 ) : To what extent is required functionality provided? Reliability ( 신뢰성 ): To what extent does the product fail? How frequently, how critical? Robustness ( 강인성 ): What happens in unexpected situations? Efficiency ( 효율성 ): How much is used of resources? Time, memory, disk, network,... Usability ( 이용도 ): How easy is the product to use? Approaches to Test Case Design Black box, or test to specifications, or functional : Checks the functionality of the software. Consider specification/requirements only. Ignore code. Glass box, or test to code, or structural : Checks the internal logic of the software. Consider code only. Ignore specification/requirements. 설계검증 (Design Verification) ED = Engineering Development DV = Design Verification PV = Production Validation CCT = Continued Compliance Testing ED ED 의목적은설계 ( 목적에맞게설계되었는지에대한 ) 타당성에대한테스팅 DV DV 의목적은제품설계가설정된설계기준 ( 규격 ) 을만족하는지에대한유효성테스팅 PV PV 의목적은생산과제작공정으로부터생산된제품이설계요구조건을만족하는지에대한검증 CCT CCT 의목적은생산된제품이설계요구조건을만족하는지주기적으로테스팅을하여제품적합성검증하는과정 Specification & Test M Specification governing test & test method used, if applicable (sometimes method is within the ethod: specification) Test Description: Acceptance Criteria: Sample Quantity: Sample Type: Provide a brief description of each test. Specify test targets and/or pass/not pass criteria, (e.g. cycles, miles, volts, min. value, no break age. etc.). If none, enter Evaluation Only. Number samples planned to be tested. Describe the samples to be tested. 17
잠시쉬어가기 IPAD2 스토리 18