Slide 1 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Welcome to Week 10 Discussion Agenda for Tonight: Review of Exam Discussion Questions from Discussion Leaders Other Questions from Students Let’s Begin …

Slide 2 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Question (25 pts.) Do CIM systems that employ Generative Computer Aided Process Planning benefit from the simultaneous use of Group Technology concepts? Yes/No Exam Review (1a)

Slide 3 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Question 1 -- cont. If so, how and/or under what conditions? (25 of 25 possible) Similar shapes/designs -> similar routings Operational Efficiencies (families, batching in families – recalculate families each period) Reduction in part variation, increase volume of common parts Reduction in tooling with reduction in parts variation, tooling cost with volume increase Exam Review (1b)

Slide 4 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Question 1 -- cont. If not, why not (20/25 max available). Generative CAPP, re-determines routing each time based on technical and economic feasibility so no permanent families established/establishable BUT -- GT makes designs similar, so algorithmically derived routings are similar and other benefits are derivable. Exam Review (1c)

Slide 5 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (2) Question 2 -- (25 pts.) Define and explain Quality Function Deployment. List and discuss its weak points. Define and Explain (15 pts.) Process to document and assess products with respect to an ordered and weighted set of customer requirements, technical specifications, the correlation of customer requirements and technical specifications, comparison to competitors, required quality (tolerances) of part, production methods. Weaknesses (10 pts.) Ability to gather customer requirements/competitor data Ability to translate requirements to specifications Ability to define correct weights/economics Can make week analysis “look” stronger than it is

Slide 6 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (3) Question 3 -- Consider the various models proposed in the text and in lecture for developing part families and manufacturing cell groupings. List, briefly define, and evaluate three (3) models/methods for cell and/or family formation (i.e., explain the philosophy/objective of each algorithm/procedure, the steps of each algorithm/procedure, and discuss its strengths and shortcomings). (8 pts each plus 1) Machine Component Group Analysis Production Flow Analysis Rank Order Clustering (King) GT Coding and Pattern Recognition Single-Linkage Cluster Analysis - Similarity Coefficients

Slide 7 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (4a) Question 4a -- (17 pts.) Consider Robots and Numerical Control Machines. Explain the similarities and differences between the two. Similarities Same basic technology, sensors Similar programming Similar function (move parts or tools in space) Similar concepts – open/closed loop, pt to pt, continuous path,multi-axis, multiple tools/parts Differences Robots less precise, accumulate error while NC more precise, axis error is independent Robot generally used for ergonomic and economic reasons, NC generally used for technological reasons

Slide 8 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (4b) Question 4 -- (8 pts.) Consider Robots and Numerical Control Machines. Briefly explain the role/use of each in FMS/Cellular Manufacturing under conditions of a) high product (design/shape) variability and low part volume (sales) as well as b) high part volume (sales) and low product (design/shape) variability. Role – high product variability/low volume Robot – allows flexibility via general purpose hand, teach or low-cost/time programming NC – allows precision manufacturing via reprogramming Role – low product variability/high volume Robot – allows labor replacement, repetitive motions NC – provides an alternative to custom, single purpose equip.

Slide 9 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (5a) Question 5 -- (25 pts.) Briefly define the life cycle and product concepts of Chris Vaughan. (15 pts.) Life Cycle Concepts: Design, Produce, Operate, Service, Dispose All products have this life cycle Iterative process (Less -> More detailed) Applies across Supply Chain (all Levels) Product Concepts: Almost everything is a product Products interact (Operate facility (product of “design and produce facility” is produces product

Slide 10 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Exam Review (5b) Question 5 -- (25 pts.) Briefly define the life cycle and product concepts of Chris Vaughan. Comprehensively discuss how his definition/concepts apply/do not apply in the practice of Concurrent Engineering. (10 pts.) Phases of life cycle define major inputs to concurrent engineering (design must consider production, operation, service and disposal of product) Iteration of design Design document(s) (product) – output/input of design facility, iterates from conceptual design to “final” design to redesign to re-redesign, … Stages of design correspond to (design) supply chain

Slide 11 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions (Jeff Short)

Slide 12 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Jeff Short ) What is the difference between JIT, MRP, and Lean Manufacturing? JIT – minimum (zero) inventory goal Absorbs fluctuations/disruptions via excess capacity (labor and machines) MRP – maximize utilization Absorbs fluctuation by planning/scheduling Lean Manufacturing – a manufacturing philosophy of efficiency which, when implemented, shortens the time between customer order and factory shipment by eliminating waste. "Uses less of everything compared with mass production” Focus on efficiency/productivity of process

Slide 13 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Jeff Short ) Chapter 10 is about MRP and Chapter 11 is concerned with JIT. These seem to be diametrically opposed views of production planning and control. What is the current state of research to resolve the philosophical disagreements and reach a more practical operating philosophy? Diametrically opposed in theoretically pure form – In practice, they blend – Balance ability to predict and preplan fluctuating vs. constant stable system (production, customer, …) No smooth/known demands (Seasonality, competitors) No smooth production (machine/managerial breakdown) No 100% availability (temporary demand exceeding capacity, rush orders) Inventory to deal with unexpected Research using each method criteria (utilization/inventory)

Slide 14 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Jeff Short ) Can JIT exist in practice for a manufacturer with high variance in demand? Yes, but if variance in demand is high, a large amount of excess production capability must be available to meet demand (on- time). As this cascades through a system, more interchangeable, cross trained workers needed with resultant higher labor costs.

Slide 15 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Jeff Short ) I understood the Wagner and Whitin Algorithm produced this property: either the inventory carried to period t+1 from period t must be zero or the production quantity in period t+1 is zero. Question 6 asks the student to begin with an inventory, obviously a violation of the W-W algorithm. I felt there were several ways to deal with this problem, all of which modified the algorithm. Which way would you suggest? Reduce demand in first period(s) to reduce inventory to zero. Is there a stochastic or fuzzy representation of the W-W algorithm?? Yes, simulation/modified Newsboy problem “goodness of solution” is determined by ability to predict period demands/distribution of demand.

Slide 16 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Jeff Short ) Both W-W and Naidu & Singh treat the variable of h, holding costs, as a well-know entity. I have never worked for/with a company that could fix the value of h for any product under all storage conditions. How is h handled in your experience? Via “Best Estimate” Usage V = value of part/product ($) h = V x (interest rate +inflation rate + insurance rate + spoilage rate + pilferage rate + management rate) + Size x (cost of space) All rates in ($/$ inv ), Cost of Space in $/unit volume Can stratify inventory (Pareto-type Analysis)

Slide 17 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions (Mike Blanton)

Slide 18 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Mike Blanton ) Problem 10.7 was difficult to do. It followed example 10.4 which was continued from example The examples seemed to leave information out, under the assumption that they were easy to follow. For me and I assume other students this was not the case. Could you please fill in the blanks. I’ll try on the next slides.

Slide 19 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Mike Blanton ) In example/problem, an LP model is solved. For 10.7 – One must first calculate the demand (d t ) In period one d t = = 260 units In common units X t = 2(50+70) + (60+80) = 380 hours This will mean k = 1 hour/unit for 380 units Perform similar calculations for other periods. Then set up LP problem:

Slide 20 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions ( Mike Blanton ) Subject to With W o =240, k=1 d 1 =380 All 0 subscripts dropped Non-negativity

Slide 21 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions (Class)

Slide 22 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Questions (Class) Other Questions as raised

Slide 23 IEM 5303 Advanced Manufacturing Systems Design  2000 John W. Nazemetz Discussion Session 10 End of Class Have a Good Week and I’ll see you next time!