Case Study 8 Andrew Kusiak 2139 Seamans Center Iowa City, Iowa 52242-1527 Tel: 319-335 5934 Fax: 319-335 5669 andrew-kusiak@uiowa.edu http://www.icaen.uiowa.edu/~ankusiak Topic Develop conceptual design of a coffee maker. erform the following: a) Elicit requirements and draw an AND/OR tree of the requirements. b) Generate functions and assign them for to the lowest level requirements of the AND/OR tree in (a) c) Draw an AND/OR tree for the functions, if necessary. d) Draw an icon representing each component. For each icon, name the inputs and outputs. e) Draw a synthesis tree. Basic Concepts AND/OR Tree - Requirements - Functions Components and Models Design Synthesis Basic Model Matching Model Team Activity Requirements Functions The following requirements are established: R1: coffee maker R2: automatic dip R3: programmable model R4: large water reservoir with a heated coffee pot stander R5: large capacity for storing coffee R6: brew basket with a filter
R7: digital clock R8: automatic shut-off R9: large water reservoir R10: heated coffee pot stander R11: store 10 cups of hot coffee R12: store 12 cups of hot coffee Requirements for a coffee maker List of Requirements R1: coffee maker R2: automatic dip R3: programmable model R1 R4: large water reservoir with a heated coffee pot stander R5: large capacity for storing coffee R6: brew basket with filter R2 R3 R7: digital clock R8: automatic shut-off R9: large water reservoir R10: heated coffee pot stander R4 R5 R6 R7 R11: store 10 cups of hot coffee R12: store 12 cups of hot coffee AND/OR R9 R10 R11 R12 Tree R8 Requirements and QFD List of Functions Functions R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 QFD Matrix F1: heat water reservoir electrically F2: heat coffee pot stander electrically F3: hold hot coffee F4: hold ground coffee and brew hot coffee F5: apply electric power to a digital clock F6: apply electric power to a shut-off module F7: apply appropriate voltage to a water reservoir F8: hold water F9: apply appropriate voltage to a coffee pot stander F12: control the display time F13: apply appropriate voltage to a shut-off module F14: control the shut off automatically F10: associate holding hot coffee with a coffee pot F11: apply appropriate voltage to a digital clock
AND/OR Functional Tree AND/OR Tree QFD again? Functions (AND/OR Tree) Main Function Sub Fun 1 Sub Fun 2 Sub Fun 3 Requirements (AND/OR Tree) QFD Matrix Requirements and functional tree F1: heat water reservoir electrically F2: heat coffee pot stander electrically F3: hold hot coffee F4: hold ground coffee and brew hot coffee F5: apply electric power to a digital clock F6: apply electric power to a shut-off module R4 R5 R2 R6 R1 R7 R3 R8 The functions are assigned the following components: C1: a supply source of different power voltages C2: a water reservoir holder C3: a heated stander with a pot R9 R10 R11 R12 R6 R7 R8 F1 F2 F3 F4 F5 F6 C4: a basket C5: a digital clock associated with a controller that shuts off the power automatically F7 F8 F9 F10 F11 F12 F13 F14 Components and the Corresponding Functions F7: apply appropriate voltage to a water reservoir F8: hold water F9: apply appropriate voltage to a coffee pot stander F10: associate holding hot coffee with a pot F3: hold hot coffee F7 F8 F9 F10 F3 F4 F11 F12 F13 F14 C1 C2 C3 C4 C5 C1: supply source of different power voltages C2: a water reservoir holder C3: a heated stander with a pot C4: a basket C5: a digital clock associated with a controller that shuts off the power automatically For each component, the following inputs and outputs are defined by the corresponding function(s): : voltage for the coffee maker C: voltage for a clock and an automatic shut-off module
: voltage for heating water : taste of coffee : clock accuracy of the automatic shut-off module : voltage for a heated stander : amount of water F: flow of hot water : temperature of hot water C: amount of ground coffee Components Components (continued) C1 C : voltage for the coffee maker C: voltage for the clock and an automatic shut-off module : voltage for the heated stander : voltage for heated water C2 : voltage for heated water : amount of water : temperature of hot water F: flow of hot water F Components (continued) C3 Step 1. MODEL_BASE {C1, C2, C3, C4, C5}. Level 1 Step 2. C1 -> C5 (rule 2, 4, and 5) C1 C C C5 F C4 C C5 : voltage for the coffee maker C: voltage for the clock and an automatic shut-off module : voltage for the heated stander : voltage for heated water : clock accuracy of the automatic shut-off module
C2 -> C4 (rule 2, 4, and 5) C2 F F C4 Step 3. Connections specified in Step 2 result in C1.C5 and C2.C4 Models and : voltage for heating water : taste of coffee : clock accuracy of the automatic shut-off module : voltage for a heated stander : amount of water F: flow of hot water Step 5. Model_Base{,, C3} Step 6. Level 2 Step 2. -> (rule 2, 4, 5, 7 and 8) Step 3. M3. Step 4. Model M3 is presented next Model M3 M3 Model M3 Step 5. Model_Base {M3, C3} Model M4 Step 6. Level 3 Step 2. M3 -> C3 (rule 2, 4, 5, 7, and 8} Step 3. M4 M3.C3 M4 Step 4. Model M4 is presented next.
Step 5. MODEL_BASE {M4} Step 6. Level 4 Step 2. No connections are generated (rule 1) Step 3. Stop The four level hierarchical tree of model M4 is Overall Model M4 M4 M3 presented next. C1 C5 C2 C4 C3 Iteration 1 Revisited M4 Applications M3 C1 C5 C2 C4 C3 Mechanical and electrical products rocess Systems (e.g., supply chain) Software C1 C C C5