CED Lect10 FunctionAnalysis by xnWgjn5

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									                          Function Analysis
Procedure for Function Analysis
   What has to be achieved by a new design
   Not on How it is to be achieved

 1. Express the Overall Function in terms of conversion of inputs to outputs.
       Black Box

 2. Break down the Overall Function into a Set of Essential Sub-Functions.

 3. Draw a Block Diagram showing Interactions of Sub-Functions.

 4. Draw System Boundary
       Functional Limits for Product to be designed
       Could be Narrowed in order to Define Feasible Product

 5. Search for Appropriate Components
    to Perform Sub-Functions & Interactions.
Procedure for Function Analysis
   Express Overall Function
      Black Box with Input & Output
      As Broad as Possible




                             BLACK BOX



           Inputs              FUNCTION               Outputs



                    Figure 1 Black Box System Model
 Procedure for Function Analysis
      Break down Overall Function
          into a Set of Essential Sub-Functions
          (Auxiliary Sub-Function)
          Depends on Factors such as Kinds of Components Available for Specific
          Tasks


                             Overall Function




Sub-            Sub-              Sub-               Sub-
Function        Function          Function           Function   …..

                      Figure 2 Break down Overall Function
Procedure for Function Analysis
   Draw Block Diagram
      Transparent Box
      Showing Interactions between Sub-Functions
      Some Sub-Functions can be Redefined
      (Different Type of Lines is useful to Show Different Types of Input &
      Output)
           Flows of Material, Energy, or Information

                            TRANSPARENT BOX
                                   Sub-                  Sub-
                                   Function              Function

             Sub-                  Sub-
             Function              Function


  Inputs                          FUNCTION

                        Figure 3 Transparent Box Model
Procedure for Function Analysis



                        BLACK BOX




                           TRANSPARENT BOX
                                  Sub-                       Sub-
                                  Function                   Function

             Sub-                 Sub-
             Function             Function




                Figure 4 Black Box & Transparent Box Model
Procedure for Function Analysis

   Draw System Boundary
      Functional Limit
      Precise Extent and Location of System Boundary
      Narrowed in order to Define Feasible Product

   Search for Appropriate Components
      Depends on Nature of Product or Device to be Designed
      (Human, Mechanical Part, or Electronic Device as Components)
Example: Feed Delivery System




       Figure 5 Existing Method of Filling, Storing and Dispatching Bags of Animal Feed
Example: Feed Delivery System
   Goal: Reduce Relative High Costs of Handling and Storing Feedstuffs
   Overall Functions Broadened
      F1. Transfer of Feed from Mixing Bin to Bags Stored in Warehouse
      F2. Transfer of Feed from Mixing Bin to Bags Loaded on Truck
      F3. Transfer of Feed from Mixing Bin to Consumers’ Storage Bin
      F4. Transfer of Ingredients from Source to Consumers’ Storage Bin
       Suggests Different Kinds of Solution




           Figure 6 Alternative Formulations of Feed Distribution Problem
 Example: Packing Carpet Squares



  Loose carpet squares                                                        Carpet squares
stamped out of the length
                                       Overall Function                        packed in lots




             Figure 7 Analysis of Principle Functions for Packing of Carpet Squares
           Example: Packing Carpet Squares


        Loose carpet squares                                                             Carpet squares
      stamped out of the length
                                                  Overall Function                        parked in lots




               Stamp
                              Separate      Check         Counts        Combine
Material        from                                                                    Pack       Dispatch
                               Offcuts      Quality       Squares        In Lots
               length

  Notation:
              Material Flow

              Main Function

              System Boundary



                        Figure 8 Analysis of Principle Functions for Packing of Carpet Squares
           Example: Packing Carpet Squares


                                                           Send Signal to
                                                         Combine n Squares
                                                                                  Supply Packing
                                                            into One Lot
                                                                                     Material




              Stamp
                          Separate       Check        Counts          Combine
Material       from                                                                   Pack         Dispatch
                           Offcuts       Quality      Squares          In Lots
              length



                           Remove       Remove
                           Offcuts      Rejects



                                                      Notation:
                                                                  Material Flow              Main Function

                                                                  Signal Flow                Auxiliary Function

                                                                  System Boundary

                       Figure 9 Expanded Function Analysis for Packing of Carpet Squares
Example: Automatic Teamaker




            Cold water                                 Hot tea
        (measured quantity)       Tea being
           Tea leaves             BREWED
        (measured quantity)                                  Tea leaves
                                                             (waste)



       Figure 10 Expanded Function Analysis for Packing of Carpet Squares
 Example: Automatic Teamaker
                      Cold water                    Hot tea
                                        Tea being
                      Tea leaves        BREWED
                                                              Tea leaves
                                                              (waste)



       Water                                                                                 Tea

(a)              Water is           Water and          Tea is                Tea and Water
       Energy
                 heated             Tea United        Infusing               are Separated
                                                                                                   Leaves
                       Tea leaves
      Water                                          Tea
                 Water is             Tea leaves
(b)   Energy     heated              are immersed
                                                                    Leaves
                       Tea leaves

                         Tea
      Water                           Tea leaves
(c)              Water is             are wetted                     Concentrate and    Tea
      Energy
                 heated                                              water are united


                Figure 11 Three Alternative Process Models for Tea Brewing
Example: Automatic Teamaker


       REGULATE                                             REGULATE
       the heating                                          the infusion



                                                                                                Tea
    Heat                          UNITE                 ALLOW                    SEPARATE
  the water                   tea and water           the infusion             tea and leaves   Leaves




       TRANSFORM                                                       ACTIVATE
       energy to heat                                                the separation


                                                                                       SUPPORT
                                                                                       subsystem



              Energy (electrical)


                         Figure 14 Function Analysis for Automatic Teamaker
Example: Washing Machine



                                               Clean clothes
          Soiled clothes
                               Washer
                                                   Dirt

                Inputs           Function          Outputs




               Figure 15 Black Box Model of Washing Machine
          Example: Washing Machine
                                         Dirty water
Soiled
Clothes




            Loosen
              dirt         Separate         Remove
                             dirt             dirt         Clean Clothes
           (add water                                      Water
              and          (agitate)         (rinse)
           detergent)




      Water Detergent                      Water

 Notation:
             Simple Washing Machine                            Washer-Dryer

             Conventional Modern Washing Machine               Future Washer-Dryer-Presser



                                Figure 16 Function Analysis of Washing Machine
          Example: Washing Machine
                                         Dirty water        Water
Soiled
Clothes




            Loosen
              dirt         Separate         Remove          Remove
                             dirt             dirt           water            Clean Clothes
           (add water                                                         Water
              and          (agitate)         (rinse)         (spin)
           detergent)




      Water Detergent                      Water

 Notation:
             Simple Washing Machine                            Washer-Dryer

             Conventional Modern Washing Machine               Future Washer-Dryer-Presser



                                Figure 16 Function Analysis of Washing Machine
          Example: Washing Machine
                                         Dirty water        Water             Moist air
Soiled
Clothes




            Loosen
              dirt         Separate         Remove          Remove              Dry
                             dirt             dirt           water            clothes
           (add water                                                                        Clean Clothes
              and          (agitate)         (rinse)         (spin)           (tumble)
           detergent)




      Water Detergent                      Water                              Hot air

 Notation:
             Simple Washing Machine                            Washer-Dryer

             Conventional Modern Washing Machine               Future Washer-Dryer-Presser



                                Figure 16 Function Analysis of Washing Machine
          Example: Washing Machine
                                         Dirty water        Water             Moist air
Soiled
Clothes




            Loosen
              dirt         Separate         Remove          Remove              Dry          Smooth
                             dirt             dirt           water            clothes        clothes
           (add water
              and          (agitate)         (rinse)         (spin)           (tumble)       (press)
           detergent)



                                                                                                        Clean
                                                                                                       Clothes
      Water Detergent                      Water                              Hot air

 Notation:
             Simple Washing Machine                            Washer-Dryer

             Conventional Modern Washing Machine               Future Washer-Dryer-Presser



                                Figure 16 Function Analysis of Washing Machine

								
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