Cost Analysis and Estimating for Engineering and Management

Cost Analysis and Estimating for Engineering and Management Chapter 7 Operation Estimating © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -1

Overview l Find Time/Cost for Production Steps l Determine Direct Labor Time l Look at a Metal Machining Example -Set Up -Cycle Time l One Time Tooling Costs l Overview of Flow Line Manufacturing © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -2

Background l “Design” Defines a Part l Design Is Broken Down into Operations l Labor & Material Determined l Cost Estimated © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -3

Definitions l Manufacturing Operations -Produce Changes to Objects to Increase Value l Cost -For Utilization of Labor & Materials to Increase Value of Some Object © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -4

Operation Estimates l Establish Costs for Components and Assemblies l Initiate Cost Reductions l Provide Standards l Compare Different Designs l Support Decisions © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -5

Operation Cost Elements © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -6

Industries l Construction Plant and Equipment Portable Output of Industry Immobile and unique © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Value of Output Expensive Ch 7 -7

Industries l Agriculture Plant and Equipment Mobile Output of Industry Moves off the plant site and is numerous © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Value of Output Inexpensive Ch 7 -8

Industries l Information Plant and Equipment Transitional and Service Output of Industry Temporary © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Value of Output Low priced Ch 7 -9

Industries l Manufacturing Plant and Equipment Fixed Output of Industry Moves off the plant site and is numerous © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Value of Output Cheap to expensive Ch 7 -10

Manufacturing Facts l Average Lot Quantity - 100 Units l Employs 16% of Population l Declining as a Percentage l Still Increasing in Absolute Numbers l Productivity Is Exceedingly High © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -11

Discrete Manufacturing l Mass Production -High Volume, Independent of Orders l Moderate Production -Large Volume, Connected to Orders, Fluctuates l Job Lot -Small Quantities (1 -500) © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -12

Operation l Series of Elements l Performed at a Single Workstation -Machine, Bench, Process l One or More Operations to Complete a Part or Assembly to a Predetermined State (per Drawing/Design) © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -13

Machining l Traditional Metal Cutting l Subject for Remaining Discussion l Set Up -Prepare Machine/Process -Includes Return to Neutral Condition l Cycle time -Run Time to Complete One Unit -Repeats © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -14

Classic Operations Analysis © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -15

Classic Operations Analysis © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -16

Modeling Machining Time l Single Point Tool - Turning Operation l Time (Cost) Is Function of: -Handling Time -Machining Time -Tool Changing Time -Tool Cost © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -17

Handling Cost l Load and Unload Work l Constant l Not Related to Cutting Time Eq 7. 1 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -18

Handling Cost © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -19

Machining Cost l Based on Cutting Speed and Feed l Controlled by Machine Setting l Shape of Part Is Changed Eq 7. 2 Eq 7. 3 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -20

Machining Cost © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -21

Tool Associated Costs l Tool Cutting Edges Wear l Wear Rate Increases with Speed l Tools Need to be Replaced/Sharpened l Takes Operator’s Time l Apportioned Over Parts Produced © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -22

Tool Changing Cost © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -23

Tool Life l Taylor’s Tool Life Equation Eq 7. 6 l Relates Tool Life to Cutting Speed l Constants Empirically Determined -For a Given Set of Conditions Only © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -24

Determining n and K © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -25

Apportioning the Tool Costs l Determine Fraction of the Tool Life Used Up on Each Part tm / T l Tool Changing Cost / Part Eq 7. 7 l Tool Cost / Part Eq 7. 8 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -26

Total Machining Time / Part Eq 7. 9 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -27

Finding Optimum Cost / Time l Minimum Machining Cost Eq 7. 10 Maximum Production Output -Ignore Tool Cost - Minimize Time Eq 7. 12 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -28

Operations Analysis l Determine -Production Quantity -Operations l Divide Operations into Elements l Determine Element Times -For Set Up and Cycle -From Data Warehouse -Add Element Times to Get Operation Time © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -29

Operations Sheet l Divides Manufacturing Process into Operations l Specifies: - Machines/Locations -Sequence -Work to Be Done in Each Operation © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -30

Steps for Operations Sheet l Interpret Engineering l Select Work Locations/Equipment l Specify Tools l Partition into Distinct Operations l Describe Each Operation l Present Information © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -31

Example Part © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -32

Example Operations Sheet l Initial Operations Sequence Workstation Op No. Description Turret lathe 10 Turn and cutoff Vertical mill 20 End mill slot Horizontal mill 30 Slab mill flat NC drill press 40 Drill and tap holes © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -33

Operations Process Plan Workstation Turret lathe Op. no. 10 Description of operation Face 0. 015 Setup hr Cycle hr/100 Lot hr Turn rough 1. 45 Turn rough 1. 15 Finish turn 1. 10 Turn 1. 735 Cutoff to 18. 75 Vertical mill 20 End mill 0. 89 slot Horizontal mill 30 Slab mill 4. 75 x 3/8 N. C. turret drill 40 Drill, tap © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -34

Set Up Description l Once per Lot l Given in Hours l Select Appropriate Elements © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Punch in and out, study drawing Hr 0. 2 Turning Equipment First tool 1. 3 Each additional tool 0. 3 Collet 0. 2 Chuck, fixture 0. 1 Ch 7 -35

Handling Time l Select Appropriate Elements l Time in Minutes (Watch Units!) Machine and Element Description Min Turning, milling, drilling Start and stop machine 0. 08 Change speed of spindle 0. 04 Inspect dimension with micrometer 0. 30 Turning equipment Cross slide advance, return, and index 0. 09 Advance stock through feed tube < 6” 0. 18 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -36

Machining Time l Majority of Cycle Time (Usually) l Machine Driven (Cutting Feed Rate) l Function of Design/Material -Amount of Material to Remove -Machine Tool(s) Used -Speeds and Feeds © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -37

Operation 10 l Set Up (from Table 7. 4) A. Setup elements Hr Punch in and out, study drawing Collet 0. 2 First facing tool 1. 3 Additional 5 tools 1. 5 Setup total, operation 10 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 0. 2 3. 2 Ch 7 -38

Op 10 - Handling l From Table 7. 5 B. Handling Min Start and stop machine 0. 08 Advance stock 0. 37 Place and remove oil guard 0. 19 Speed changes, assume 4 x 0. 04 End turret 5 x 0. 08 0. 16 Cross slide advance, return 0. 09 Inspect part with micrometer, irregular 1/5 x 0. 30 Subtotal of handling and equipment elements 0. 06 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 0. 40 1. 35 Ch 7 -39

Facing Elem Depth of Cut Ld Face 0. 015 0. 875 Ls 1/32 L D V fpm . 906 1. 750 350 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management F (ipr) tm, min . 007 0. 17 Ch 7 -40

First Rough Turn Elem Dim Depth of Cut Rough turn 1. 45 0. 15 Ld Ls L D V fpm 16. 5 1/32 16. 5 1. 75 350 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management f (ipr) tm min . 015 1. 44 Ch 7 -41

Second Rough Turn Elem Dim Depth of Cut Rough turn 1. 15 0. 15 Ld Ls L D V fpm 16. 5 1/32 16. 5 1. 45 350 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management f (ipr) tm min . 015 1. 19 Ch 7 -42

Remaining Elements © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -43

Cycle Times for Remaining Elems Elem Dim Depth of Cut Ld Ls L D V fpm F (ipr) tm, min Finish turn 1. 10 0. 025 16. 5 1/32 16. 53 1. 15 350 007 2. 03 Elem 5 Turn 1. 73 . 0075 0. 5 1/32 0. 53 1. 75 350 007 0. 10 Cutoff 1. 75 . 875 1/32 0. 906 1. 75 350 015 0. 08 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -44

Operation 10 Totals Subtotal of machining times 5. 01 Total cycle time for handling and machining 6. 36 D. Entry values for operation sheet, operation 10 Setup hr Hr/100 units © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 3. 2 10. 600 Ch 7 -45

Calculating Length of Cut l For Rotating Cutters l Length of Travel at Feed Rate Eq 7. 14 l Safety Length -For Stock and Mounting Variations © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -46

Other Length Factors l Approach/Over Travel -Gets Cutter Fully Into & Out of Work -Many Times = Cutter Radius but… -Over Travel May Not Be Required l Design Length -Actual Length Making Cut -Include All Passes and Lateral Moves © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -47

End Mill Length of Cut © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -48

Peripheral Cutting Length © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -49

Approach Length Differs l Peripheral Milling Need to Consider: -Cutter Diameter -Depth of Cut Eq 7. 15 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -50

Drilling l Approach Includes Point Angle Eq 7. 16 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -51

Operation 20 l Set Up (from Table 7. 4) A. Setup elements Hr Punch in and out, study drawing 0. 2 Slot-cut milling collet 1. 6 Setup total, operation 20 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 1. 8 Ch 7 -52

Handling l From Table 7. 5 B. Handling and other equipment time elements Start and stop machine Min 0. 08 Air clean part 0. 06 10 lb < 15 lb load into collet 0. 25 Open and close air vise 0. 06 Change speeds and feeds, 2 x 0. 08 Subtotal of handling © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 0. 53 Ch 7 -53

End Milling © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -54

End Milling Times Element Ld Milling Cutter Rough mill slot 6. 81 0. 75 in. end mill, 4 flute 85 0. 002 1. 97 Finish mill slot 6. 81 0. 75 in. end mill, 4 flute 95 0. 0015 2. 34 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management V fpm ft (itpr) tm, , min Ch 7 -55

Operation 20 Totals Subtotal of machining times 4. 31 Total cycle time for handling and machining, min 4. 84 D. Entry values for operation sheet, operation 20 Setup hr Hr/100 units © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 1. 8 8. 067 Ch 7 -56

Operation 30 l Set Up (from Table 7. 4) A. Setup elements Hr Punch in and out, study drawing 0. 2 Special vise 1. 1 Setup total, operation 30 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 1. 3 Ch 7 -57

Handling l From Table 7. 5 B. Handling and other equipment time elements Start and stop machine Min Air clean part 0. 06 10 lb < 15 lb load into collet fixture 0. 25 Open and close air vise 0. 06 Subtotal of handling and other equipment © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 0. 08 0. 45 Ch 7 -58

Peripheral Milling © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -59

Length of Cut l Peripheral Milling -Use Equation 7. 15 for Approach and OT Cutter 4” Dia, Depth of Cut = 3/8” l Ld = 1. 05, La = Lot = 1. 2 (Ls in Rounding of La) l L = 1. 05 + 2(1. 2) = 3. 45 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -60

Peripheral Milling Times Element Ld Mill flat on end 3. 45 Milling Cutter V fpm ftd (itpr) 4 in. O. D. , 8 tooth 210 0. 005 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management tm 0. 43 Ch 7 -61

Operation 30 Totals Subtotal of machining times 0. 43 Total cycle time for handling and machining, min 0. 88 D. Entry values for operation sheet, operation 30 Setup hr Hr/100 units © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 1. 3 1. 467 Ch 7 -62

Operation 40 l Set Up (from Table 7. 4) A. Setup elements Punch in and out, study drawing First turret station for drill Second turret station for tap Collet for holding Setup total, operation 40 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Hr 0. 2 0. 75 0. 07 0. 1 1. 12 Ch 7 -63

Handling l From Table 7. 5 B. Handling and other equipment time elements Start and stop machine Min 0. 08 Air clean part 0. 06 10 lb < 15 lb load/unload part into collet 0. 22 Open and close air collet clamping 0. 05 Index turret, 2 x for drilling and tapping 0. 06 Raise tool, move to new locations, 8 x 0. 48 Subtotal of handling and other equipment © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 0. 95 Ch 7 -64

Drilling © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -65

Drilling Time Tool Drill, 5/16 Tap, 3/8 – 16 Ld fdt Lfdt No. holes tm, , min 0. 63 0. 61 0. 38 4 1. 52 0. 5 0. 33 0. 17 4 0. 66 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -66

Operation 40 Totals Subtotal of machining times 2. 18 Total cycle time for handling and machining, min 3. 13 D. Entry values for operation sheet, operation 40 Setup hr Hr/100 units © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management 1. 12 5. 217 Ch 7 -67

Post All of the Times Op. no. Setup hr Cycle hr/100 units Lot Hr (Qty = 200) 10 3. 2 10. 600 24. 4 20 1. 8 8. 067 17. 9 30 1. 3 1. 467 2. 9 40 1. 12 5. 217 10. 4 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -68

Tool Cost l Tools Facilitate Manufacturing l Tool Cost Is Part of Operation Cost l Tools – Permanent, One-Time Cost -Nonrecurring, Initial Fixed Cost l Tools Require Engineering Design l Tools Can Be a Large Cost © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -69

Tool Cost Estimating l Simple Methods -Standard Time Data -Use Tables -Broad, General Categories l One Time Cost -Estimate Less Critical -Usually Hours Is the Increment © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -70

Drill Jig Example © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -71

Drill Jig Cost Description of tool elements Angular base plate, C-angle Guide bushing Hinge plate Clamp with screw Feet, 3 Pin locators, 5 Total Productive hour cost for tool making Cost of tool, 44. 8 x 75 Material cost, $25/lb Total cost of tool © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Hr 7. 0 2. 0 12. 0 7. 5 8. 8 44. 8 $75 $3360 200 $3560 Ch 7 -72

What to Do with Tool Costs l Add to Overhead (NOT Recommended) l Amortize Over Production Eq 7. 18 l. N Is Critical -Too Small N, Tooling Cost Too High -Too Large N, Tooling May Not Be Paid For © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -73

Tooling vs. No Tooling l Compare Manufacturing Cost -Using Tooling (Saves Labor) -Without Tooling (Additional Labor) Eq 7. 19 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -74

Calculate the Operation Cost l Batch Manufacturing Situation l Determine Hours for the Lot Eq 7. 20 l Find the Batch (Lot) Cost Eq 7. 21 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -75

Total Product Manufacturing Cost l Cost for All Operations l Include Material and Tooling Costs Eq 7. 22 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -76

Cost for Pinion Example Lot Op. no. Lot hr PHC 10 24. 4 39. 16 $955 $4. 78 20 17. 9 90. 98 $1631 $8. 16 30 2. 9 90. 98 $267 $1. 34 40 10. 4 39. 16 $409 $2. 04 Total Lot Cost $3262 cost Unit Production Cost Total Unit Cost (incl. $21. 43 Matl) © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Unit cost $16. 32 $37. 66 Ch 7 -77

Flow Line Manufacturing l Mass Production, Assembly Lines l All Operations Interdependent l Times Determined from Station Requiring the Longest Time l Imbalance Leads to Idle Time for Other Stations © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -78

Flow Line Set Up Time l Find l Total Maximum Station Set Up Time Cost for Line Set Up © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Eq 7. 23 Ch 7 -79

Flow Line Cycle Time l Find l Total Maximum Station Cycle Time Cost for Line Cycle Time Eq 7. 24 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -80

Total Product Time (Flow Line) l Determine Lot Hours Eq 7. 25 l If n. SUf is Very Small Compared to n. NHf -Set Up Cost Can Be Ignored -Covered in Overhead © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -81

Total Product Cost (Flow Line) l Total Labor Cost Eq 7. 26 l Total Product Cost Eq 7. 27 © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -82

Summary l Determined Costs for Manuf. Operations l Found Direct Labor Times -Set Up and Cycle Times -Machining Time l Studied a Metal Machining Example l Added Tooling Costs l Briefly Looked at Flow Line Costs © 2004 Pearson Education, Inc. Pearson Prentice Hall, Pearson Education, Upper Saddle River, NJ 07458 Ostwald and Mc. Laren / Cost Analysis and Estimating for Engineering and Management Ch 7 -83