Defining and solving design problems

1. Designing products and process plants Product anatomy Components: standard vs. special purpose Process plant anatomy Component decomposition diagrams Types of design Tinkering Summary Defining and solving design problems

2. laser printer leaf rake paper clip paper cup penlight power lawn mower toaster oven vacuum cleaner automobile baseball bat bicycle canoe paddle coffee maker commercial jet fishing reel inflatable kayak Are all design problems the same? Imagine designing the following products

3. Let’s start with product design A product is an item that is purchased and used as a unit (Dixon and Poli, 1995)

4. case button spring battery bulb cap Example product…. Penlight has “components”

5. penlight bulb battery body screw cap switch glass lens filament base anode cathode electrolyte plastic cover case spring Component decomposition diagram - penlight Parts Assemblies Standard Special purpose A diagram showing the anatomy

6. Standard Parts Standard Assemblies Special Purpose Parts bolt, nut screw rivet key gasket gear blank lubricant seal pump electric motor clutch chain/sprocket heat exchanger brake caliper ball bearing power screw housing cover bracket link support shaft Other example components

7. Product Standard Part Special purpose Part Sub-assembly A Sub-assembly B Special purpose part Special purpose part Standard part Sub-assembly B1 Standard part Special purpose part General product – component decomposition

8. Final design (not included in text) • Communication book: letters, emails, minutes. • Technical info book: catalogs, articles. • Design book: math models, optimization problems. • Plan book: assemblies, parts, list of standard and special-purpose parts.

9. Process plant - definition A process plant is a combination of systems used to process energy or materials (both organic and inorganic).

10. Frozen Vegetable Plant Washing System Blanching System Freezing System Packaging System Spraying Parboiling Chilling Weighing Conveying Cooling Inspecting Wrapping Inspecting Conveying Inspecting Component decomposition of a frozen food processing plant Plant System Equipment

11. Equipment 5 Plant Equipment 1 System A System B Equipment 2 Equipment 4 Sub-system B1 Equipment 3 Component decomposition of process plant

12. Why bother preparing Component Decomposition Diagrams? • Understand the interaction between components • Consider standard parts versus special purpose parts (buy vs. make) • Divide the design problem into separate sub-problems, i.e. decisions. • Learn pros & cons of existing products or processing plants

13. Types of design (i.e. decisions and activities) modifying the “form” choosing from existing standard parts/subassemblies modifying existing part/subassembly, but keeping original concept adapting known solution to new task  new concept, part never existed before modifying appearance or look vs. assembly or product design Redesign – Selection design – Variant design – Adaptive design – Original design – Artistic design - Part design –

14. Types of design related to phase Formulation original design selection design part design Concept Design variant design Configuration Design Configuration Design Parametric Design Parametric Design Parametric Design Detail Design Detail Design Detail Design Detail Design

15. “Tinker” Date: 1592---to work in the manner of a tinker; especially: to repair, adjust, or work with something in an unskilled or experimental manner: to FIDDLE (http://www.m-w.com/cgi-bin/dictionary) Real engineers do not tinker. Real engineers predict how a product will perform before building it, reducing the need to “cut and try” or “fiddle.”

16. Summary • Products and process plants have an anatomy of components • Components include parts & subassemblies • Process plant components include systems and equipments • Components can be standard or special purpose • Component decomposition diagrams are very useful • Types of design include: original, variant, selection, adaptive, redesign • Tinkering is really not engineering design