OVERVIEW Debate in engineering design community: Should design be taught as: Establishing a foundation of theory? or Engaging students in loosely supervised practice? Reject both approaches when taken to extremes Theory without practice is ineffective because there are many nuances, exceptions, and subtleties to be learned in practical settings Practice without guidance can be very frustrating and often fails to exploit knowledge and expertise Focus on methodology Step-by-step procedure for completing a task Does not embody a clean and concise theory 11/14/2018 MAE 4291: Senior Design 1

PRODUCT DEVELOPMENT PROCESS 11/14/2018 MAE 4291: Senior Design 1

GENERIC DEVELOPMENT PROCESS Concept Development Identifying customer needs Establishing target specifications Analysis of competitive products Concept generation Concept selection Refinement of specifications Economic analysis Project planning A concept is a description of the form, function, and features or a product and is usually accompanied by a set of specifications, an analysis of competitive products, and an economic justification for the project 11/14/2018 MAE 4291: Senior Design 1

GENERIC DEVELOPMENT PROCESS System Level Design Definition of the product architecture and the division of the product into subsystems and components Output: Geometrical layout of the product Functional specification of each of the products subsystems Preliminary process flow diagram for assembly 11/14/2018 MAE 4291: Senior Design 1

GENERIC DEVELOPMENT PROCESS Detailed Design Complete specification of geometry, materials, and tolerances for all parts Identification of all of the standard parts to be purchased from suppliers Output Control documentation: drawings (or computer files) describing all details of the geometry of each part and tooling specifications 11/14/2018 MAE 4291: Senior Design 1

GENERIC DEVELOPMENT PROCESS Testing and Refinement Construction and evaluation of multiple versions (prototypes) of the product Alpha prototype: determine whether or not the product will work as designed and whether or not product meets customer needs Beta prototype: extensively evaluated internally and examine performance and reliability to identify changes prior to final design 11/14/2018 MAE 4291: Senior Design 1

MAE HISTORICAL OBSERVATIONS Many (perhaps even most) MAE senior design teams get stuck in (1) and (2) and not enough effort is placed in (3) and (4) Good connection between (1) and (2) Significant disconnect between how (3) and (4) fit into (1) and (2) Significant disconnect between how (3) and (4) go together 11/14/2018 MAE 4291: Senior Design 1

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EXAMPLE OF PROJECT PLAN 11/14/2018 MAE 4291: Senior Design 1

ESTABLISHING SPECIFICATIONS

EXAMPLE: MOUNTAIN BIKE FRONT SUSPENSION Example of customer specified needs Includes importance relative importance 5 most important, 1 least important Note how vague statements are, and how much margin for subjective interpretation Example: “Suspension is easy to install” versus “the average time to assemble the fork to the frame is less than 75 seconds” 11/14/2018 MAE 4291: Senior Design 1

EXAMPLE: MOUNTAIN BIKE FRONT SUSPENSION 11/14/2018 MAE 4291: Senior Design 1

NEEDS – METRICS MATRIX Shows relationship between needs and metrics and assures that all of customer needs are considered Often called ‘House of Quality’ – graphical technique Metrics are dependent varaibles Metrics should be practical 11/14/2018 MAE 4291: Senior Design 1

COMPETITIVE BENCHMARKING Very important for commercial products in a competitive market place (unless you have a monopoly) Compare other products with the metrics that you have determined Use this information to rank other products 11/14/2018 MAE 4291: Senior Design 1

TARGET SPECIFICATIONS Now have a quantitative measure of how to meet customer needs Will facilitate development of technical and cost models Will inherently be refined as design process continues 11/14/2018 MAE 4291: Senior Design 1

EXAMPLE OF TECHNICAL MODELS What design variables do you have that can control the metrics? Foundation for the development of a ‘serious’ math model 11/14/2018 MAE 4291: Senior Design 1

CONCEPT GENERATION

EXAMPLE: NAILGUN Understanding the problem External searches Literature review Talking to companies Internal searches Individual and group ideas Systematically assess each concept 11/14/2018 MAE 4291: Senior Design 1

EXAMPLES OF CLASSIFICATION Classification tree for nailer energy sources Problem deomposition assuming an electrical energy source and accumulation of energy in mechanical domain and concept combination table 11/14/2018 MAE 4291: Senior Design 1

POTENTIAL CONCEPTS Concept 1 Concept 2 Concept 3 Concept 1: solenoid compresses a spring and then releases it repeatedly in order to drive the nail with multiple impacts Concept 2: multiple solutions arising from combination for a motor with transmission – motor winds a spring, accumulating potential energy which is delivered to the nail in a single blow Concept 3: combination of motor with transmission – motor repeatedly winds and releases the spring, driving the nail with multiple blows. 11/14/2018 MAE 4291: Senior Design 1

CONCEPT RANKING AND SELECTION Example of concept screening matrix Develop your own ranking methodology The process is what is important 11/14/2018 MAE 4291: Senior Design 1