Process design layout ppt bec doms

1. Process Design and Facility Layout

4. Process Selection and System Design Figure 6.1 Forecasting Product and Service Design Technological Change Capacity Planning Process Selection Facilities and Equipment Layout Work Design

7. Product – Process Matrix Dimension Job Shop Batch Repetitive Continuous Job variety Very High Moderate Low Very low Process flexibility Very High Moderate Low Very low Unit cost Very High Moderate Low Very low Volume of output Very low Low High Very high

8. Job Shop Batch Repetitive assembly Continuous Flow Variety, Flexibility, & Volume

9. Product – Process Matrix Process Type High variety Low variety Job Shop Appliance repair Emergency room Batch Commercial bakery Classroom Lecture Repetitive Automotive assembly Automatic carwash Continuous (flow) Oil refinery Water purification

10. Product-Process Matrix Flexibility-Quality Dependability-Cost Continuous Flow Assembly Line Batch Job Shop Low Volume One of a Kind Multiple Products, Low Volume Few Major Products, Higher Volume High Volume, High Standard- ization Book Writing Movie Theaters Automobile Assembly Sugar Refinery Flexibility- Quality Dependability- Cost

12. Robot Show wafer_handler_web

18. The Need for Layout Decisions Inefficient operations For Example: High Cost Bottlenecks Changes in the design of products or services The introduction of new products or services Accidents Safety hazards

19. The Need for Layout Design (Cont’d) Changes in environmental or other legal requirements Changes in volume of output or mix of products Changes in methods and equipment Morale problems

22. A U-Shaped Production Line Advantage: more compact, increased communication facilitating team work, minimize the material handling

23. Process Layout Used for Intermittent processing Process Layout (functional) Dept. A Dept. B Dept. D Dept. C Dept. F Dept. E

24. Process Layout Process Layout - work travels to dedicated process centers Milling Assembly & Test Grinding Drilling Plating

25. Layout types: Product or Process Make your pick A B A B

29. A Group of Parts Similar manufacturing characters

30. Process vs. Cellular Layouts Dimension Process Cellular Number of moves between departments many few Travel distances longer shorter Travel paths variable fixed Job waiting times greater shorter Amount of work in process higher lower Supervision difficulty higher lower Scheduling complexity higher lower Equipment utilization Lower? Higher?

31. Process Layout Gear cutting Mill Drill Lathes Grind Heat treat Assembly 111 333 222 444 222 111 444 111 333 1111 2222 222 3333 111 444 111 333333333 44444 333333 22222

32. Cellular Manufacturing Layout -1111 -1111 222222222 - 2222 Assembly 3333333333 - 3333 44444444444444 - 4444 Lathe Lathe Mill Mill Mill Mill Drill Drill Drill Heat treat Heat treat Heat treat Gear cut Gear cut Grind Grind

36. Design Product Layouts: Line Balancing Line balancing is the process of assigning tasks to workstations in such a way that the workstations have approximately the same processing time requirements. This results in the minimized idle time along the line and high utilization of labor and equipment . Cycle time is the maximum time allowed at each workstation to complete its set of tasks on a single unit What is the cycle time for the system above? Each task takes 1 minutes, how to balance? Worker 1 Worker 2 4 tasks 2 tasks

37. Parallel Workstations 1 min. 2 min. 1 min. 1 min. 30/hr. 30/hr. 30/hr. 30/hr. 1 min. 2 min. 1 min. 1 min. 60/hr. 30/hr. 30/hr. 60/hr. 2 min. 30/hr. 30/hr. Bottleneck Parallel Workstations

39. Cycle Time The major determinant: cycle time Minimum cycle time: longest task time by assigning each task to a workstation Maximum cycle time: sum of the task time by assigning all tasks to a workstation Cycle time is the maximum time allowed at each workstation to complete its tasks on a unit.

40. Determine Maximum Output Cycle Time: Time to process 1 unit Example: If a student can answer a multiple choice question in 2 minutes but gets a test with 30 questions and is given only 30 minutes then OT=30 minutes; D=30 Desired cycle time=1 minute < 2 minutes = Cycle time from the process capability

41. Determine the Minimum Number of Workstations Required: Efficiency Example: Students can answer a multiple choice question in 2 minutes but given a test with 30 questions and is given only 30 minutes. What is the minimum number of students to collaborate to answer all the questions in the exam? Total operation (task) time = 60 minutes = 30 x 2 minutes Operating time=30 minutes 60/3=2 students must collaborate. This N min below.

42. Percent Idle Time Efficiency = 1 – Percent idle time

43. Example 1: Precedence Diagram Precedence diagram : Tool used in line balancing to display elemental tasks and sequence requirements a b c d e 0.1 min. 0.7 min. 1.0 min. 0.5 min. 0.2 min.

45. Solution to Example 1. Assigning operations by the number of followers - Eligible operation fits into the remaining time and its predecessors are already assigned . - What is the minimum cycle time possible for this example?

46. Calculate Percent Idle Time Efficiency=1-percent idle time=1-0.167=0.833=83.3%

48. Solution to Example 1. Assigning operations using their task times. Eligible operation fits into the remaining time and its predecessors are already assigned .

50. Solution to Example 1. Assigning operations using their task times. Eligible operation fits into the remaining time and its predecessors are already assigned .

51. Example 2 c d a b e f g h 0.2 0.2 0.3 0.8 0.6 1.0 0.4 0.3

52. Solution to Example 2 Station 1 Station 2 Station 3 Station 4 a b e f d g h c

57. Example 3: Layout Alternative 1 1 3 2 30 170 100 A B C Total Distance Traveled by Material=7600 m

58. Example 3: Layout Alternative 2 1 2 3 170 30 100 A B C Total Distance Traveled by Material=10400 m

59. Closeness Rating : multiple criteria

64. An example for Recitation Tasks times and predecessors for an operation C D A G J K E L F B I M H N Task label Time Predecessors A 2 None B 7 A C 5 None D 2 None E 15 C,D F 7 A,E G 6 None H 4 B,G I 9 A J 10 None K 4 None L 8 J,K M 6 A,L N 15 F,H,I,M

66. Solution 1: Greatest task time first Station Time remaining Eligible Assign Idle Time 1 17 C,D,A,G,J,K J 7 C,D,A,G,K G 1 2 17 C,D,A,K C 12 D,A,K K 8 D,A,L L 0 3 17 D,A A 15 D,B,I,M I 6 D,B,M M 0 4 17 D,B B 10 D,H H 6 D D 4 5 17 E E 2 6 17 F F 10 7 17 N N 2 A 2 None B 7 A C 5 None D 2 None E 15 C,D F 7 A,E G 6 None H 4 B,G I 9 A J 10 None K 4 None L 8 J,K M 6 A,L N 15 F,H,I,M

68. Solution 3: Greatest positional weight first OPERATION SUCCESSORS' TASK TIME TASK TIME C 42 5 D 39 2 J 39 10 E 37 15 K 33 4 L 29 8 A 28 2 B 26 7 G 25 6 I 24 9 F 22 7 M 21 6 H 19 4 N 15 15 STATION NO OPERATIONS STATION TIME 1 C,D,J 17 2 E,A 17 3 K,L 12 4 B,G,H 17 5 I,F 16 6 M 6 7 N 15