25-Comp-B8 Computer Integrated Manufacturing · May 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
98-Comp-B8, Computer Integrated Manufacturing — National Exams, May 2015. Open-book, 3 hours, non-communicating calculator permitted; six questions of equal value (each 20%), most requiring an essay-format answer; ANY FIVE constitute a complete exam (all six answered below as a complete study resource).
Reference texts: Groover, Automation, Production Systems, and Computer-Integrated Manufacturing, 4th ed. — numerical control (Ch.6–7, Q1), industrial robotics and control resolution (Ch.8, Q2), artificial intelligence and process planning in manufacturing (Ch.24–25, Q3–Q5), computer-integrated manufacturing and manufacturing cells (Ch.1, 19, 24–25, Q4–Q5), and flexible manufacturing systems (Ch.19, Q6); Kalpakjian & Schmid, Manufacturing Engineering and Technology, 7th ed. — CAD/CAM and process planning (Ch.38–39, Q4).
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.
A variant CAPP system is built around group-technology classification and coding: parts are assigned a code describing their shape and processing attributes, similar parts are grouped into families, and a standard "master" route sheet is created and stored for each family. When a new part arrives, its code is used to retrieve the family's master plan, and a human planner edits it (dimensions, feeds/speeds, minor operation changes) to suit the specific part. It relies entirely on a pre-existing library of family plans and a working coding/classification system, is comparatively inexpensive and quick to implement, and remains, in effect, a retrieval-and-edit tool rather than an automatic planner.
A generative CAPP system synthesizes a process plan automatically for each new part by applying decision logic — algorithms or expert-system rules — to the part's geometric and technological features (extracted from its CAD model), without needing any existing family plan on file. It requires substantially more upfront development effort to encode a plant's manufacturing capability and logic comprehensively, and is technically more complex, but it scales cleanly to high part variety and adapts automatically as new part configurations appear, which a variant system's fixed library cannot do without manual additions.
A routing sheet (operation or route sheet) is the process-planning document that lists, for a given part, the ordered sequence of operations and the work centre or machine assigned to each; the required tooling, fixtures, and cutting parameters (speed, feed, depth of cut) per operation; the standard time allowed for each operation; the department or area the part is routed through; and the inspection points and quality requirements along the way. It is necessary because it is the single authoritative instruction that governs how a part actually moves and is processed through the shop: without it there is no formal, auditable basis for scheduling operations and equipment, for estimating and controlling production cost, for planning capacity, or for verifying that the part was made the way it was intended to be — every downstream shop-floor and business function (scheduling, cost accounting, quality control, capacity planning) consumes the routing sheet as its source of truth for that part.
A manufacturing cell is a group of several — usually dissimilar — machines or workstations physically arranged together and dedicated to producing a specific family of similar parts (identified through group technology), with material moved between the machines by a simple, often automated, handling arrangement (conveyor, robot, or manual transfer over short distances). It was developed to close the gap between the two traditional extremes of shop layout: a purely functional (process) layout groups similar machines together and offers flexibility for high part variety, but generates long, complex material flows, large work-in-process inventories, and long lead times; a dedicated flow line offers very high efficiency but only for one product at high volume. The manufacturing cell captures much of the flow-line's reduced material handling, work-in-process, and lead time while retaining enough flexibility, through its focus on a part family rather than a single part, to remain economical over the medium-volume, medium-variety range of production that neither extreme layout serves well.
