23-Mechatronics-B8 Product Design and Development · December 2019
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams, 16-Mex-B8, Product Design and Development — December 2019, 3 hours, open-book examination (Casio or Sharp approved calculator only). Question 1 (40 marks) is mandatory; candidates choose 4 of the remaining 6 questions (15 marks each, only the first five questions as they appear in the answer book are marked, for a total of 100%). This is an essay/design-methodology paper with no numerical calculations. All seven questions are answered below for completeness.
Reference texts: Ulrich, Eppinger & Yang, Product Design and Development, 7th ed. (generic product-development process, concept generation and selection, Design for Manufacturing and Assembly, intellectual-property strategy); Government of Canada, Canadian Intellectual Property Office (CIPO), A Guide to Patents (Patent Act novelty/ utility/non-obviousness requirements, first-to-file rule, maintenance fees); Transport Canada, Motor Vehicle Safety Act and Canada Motor Vehicle Safety Standards (CMVSS).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
Design, functionally defined, is the decision-making process that transforms a set of stated user needs and technical requirements into a specific, producible physical or system embodiment capable of performing those functions reliably, safely and economically. It is not the styling of a product but the full chain of decisions — from requirements, through concept generation and selection, to a detailed, manufacturable specification — that determines whether the resulting artifact actually does what it was meant to do.
Take a configurable cordless power-tool platform (one motor/battery/gearbox core sold with interchangeable attachment heads — drill, driver, saw). Its functional design features are the ones that determine whether it performs its job: motor power and torque curve, gear ratio, the mechanical/electrical attachment interface between core and head, and safety interlocks that prevent operation with an improperly seated attachment. Its aesthetic features — housing colour, shape, surface finish and branding — determine how the product is perceived and differentiated on the shelf, but do not by themselves make it work. The designer rationalizes the two by sequencing the work: functional requirements are established first (via Quality Function Deployment, translating customer needs like "powerful enough for deck screws" into measurable specifications such as torque and no-load speed), and the housing/aesthetic design is then developed within the envelope those functional decisions impose (for example, the housing shape must still provide adequate ventilation for motor cooling and clearance for the interlock mechanism). Successive prototypes and user testing are used to check that aesthetic choices have not silently compromised a functional requirement, and the design is only frozen once both sets of requirements are simultaneously satisfied.
(1) Dimensional and geometric tolerances with clear datum references (GD&T), so that a part made by one team mates correctly with a part made by another without physical trial-fitting. (2) Material specification and any required finish or surface treatment, since strength, weight and compatibility with a mating part (e.g. galvanic compatibility of two metals in contact) depend on it. (3) Interface/mating-feature callouts — fastener sizes and types, fit class, and the specific connection points referenced against the assembly drawing/bill of materials — so that engineers on different sub-teams, who may never speak to each other directly, can be confident their parts will assemble as an integrated system.
