Process Selection and Facility Layout

1. 6 Process Selection and Facility Layout

2. Learning Objectives • Explain the strategic importance of process selection. • Explain the influence that process selection has on an organization. • Describe the basic processing types. • Discuss automated approaches to processing. • Explain the need for management of technology.

3. Learning Objectives • List some reasons for redesigning layouts. • Describe the basic layout types. • List the main advantages and disadvantages of product layouts and process layouts. • Solve simple line-balancing problems. • Develop simple process layouts.

4. Introduction • Process selection • Deciding on the way production of goods or services will be organized • Major implications • Capacity planning • Layout of facilities • Equipment • Design of work systems

5. Process Selection and System Design Facilities andEquipment CapacityPlanning Forecasting Layout Product andService Design ProcessSelection WorkDesign TechnologicalChange Figure 6.1

6. Process Strategy • Key aspects of process strategy • Capital intensive – equipment/labor • Process flexibility • Technology • Adjust to changes • Design • Volume • Technology

7. Technology • Technology: The application of scientific discoveries to the development and improvement of products and services and operations processes. • Technology innovation: The discovery and development of new or improved products, services, or processes for producing or providing them.

8. Kinds of Technology • Operations management is primarily concerned with three kinds of technology: • Product and service technology • Process technology • Information technology • All three have a major impact on: • Costs • Productivity • Competitiveness

9. Technology Competitive Advantage • Innovations in • Products and services • Cell phones • PDAs • Wireless computing • Processing technology • Increasing productivity • Increasing quality • Lowering costs

10. Technology Acquisition • Technology can have benefits but … • Technology risks include: • What technology will and will not do • Technical issues • Economic issues • Initial costs, space, cash flow, maintenance • Consultants and/or skilled employees • Integration cost, time resources • Training, safety, job loss

11. Process Selection • Variety • How much • Flexibility • What degree • Volume • Expected output Batch Job Shop Repetitive Continuous

12. Process Types • Job shop • Small scale • Batch • Moderate volume • Repetitive/assembly line • High volumes of standardized goods or services • Continuous • Very high volumes of non-discrete goods

13. Product and Service Processes Figure 6.2 Low Volume High

14. Product and Process Profiling • Process selection can involve substantial investment in • Equipment • Layout of facilities • Product profiling: Linking key product or service requirements to process capabilities • Key dimensions • Range of products or services • Expected order sizes • Pricing strategies • Expected schedule changes • Order winning requirements

15. Automation • Automation: Machinery that has sensing and control devices that enable it to operate • Fixed automation • Programmable automation

16. Automation • Computer-aided design and manufacturing systems (CAD/CAM) • Numerically controlled (NC) machines • Robot • Manufacturing cell • Flexible manufacturing systems (FMS) • Computer-integrated manufacturing (CIM)

17. Facilities Layout • Layout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system • Product layouts • Process layouts • Fixed-position layout • Combination layouts

18. Objective of Layout Design • Facilitate attainment of product or service quality • Use workers and space efficiently • Avoid bottlenecks • Minimize unnecessary material handling costs • Eliminate unnecessary movement of workers or materials • Minimize production time or customer service time • Design for safety

19. Importance of Layout Decisions • Requires substantial investments of money and effort • Involves long-term commitments • Has significant impact on cost and efficiency of short-term operations

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

21. The Need for Layout Design Changes in environmental or other legal requirements Changes in volume of output or mix of products Morale problems Changes in methods and equipment

22. Basic Layout Types • Product layouts • Process layouts • Fixed-position layout • Combination layouts

23. Basic Layout Types • Product layout • Layout that uses standardized processing operations to achieve smooth, rapid, high-volume flow • Process layout • Layout that can handle varied processing requirements • Fixed-position layout • Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed

24. Product Layout Figure 6.4 Raw materials or customer Station 2 Station 3 Station 4 Finished item Station 1 Material and/or labor Material and/or labor Material and/or labor Material and/or labor Used for Repetitive or Continuous Processing

25. Advantages of Product Layout • High rate of output • Low unit cost • Labor specialization • Low material handling cost • High utilization of labor and equipment • Established routing and scheduling • Routing accounting and purchasing

26. Disadvantages of Product Layout • Creates dull, repetitive jobs • Poorly skilled workers may not maintain equipment or quality of output • Fairly inflexible to changes in volume • Highly susceptible to shutdowns • Needs preventive maintenance • Individual incentive plans are impractical

27. A U-Shaped Production Line 1 2 3 4 In 5 Workers 6 Out 10 9 8 7 Figure 6.6

28. Process Layout Dept. A Dept. C Dept. E Dept. B Dept. D Dept. F Figure 6.7 Process Layout (functional) Used for Intermittent Processing Job Shop or Batch Processes

29. Product Layout Work Station 1 Work Station 2 Work Station 3 Figure 6.7 (cont’d) Product Layout (sequential) Used for Repetitive Processing Repetitive or Continuous Processes

30. Advantages of Process Layouts • Can handle a variety of processing requirements • Not particularly vulnerable to equipment failures • Equipment used is less costly • Possible to use individual incentive plans

31. Disadvantages of Process Layouts • In-process inventory costs can be high • Challenging routing and scheduling • Equipment utilization rates are low • Material handling slow and inefficient • Complexities often reduce span of supervision • Special attention for each product or customer • Accounting and purchasing are more involved

32. Fixed-Position Layouts • Fixed-position Layout: Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed • Nature of the product dictates this type of layout • Weight • Size • Bulk • Large construction projects

33. Cellular Layouts • Cellular Production • Layout in which machines are grouped into a cell that can process items that have similar processing requirements • Group Technology • The grouping into part families of items with similar design or manufacturing characteristics

34. Functional vs. Cellular Layouts Table 6.3

35. Service Layouts • Warehouse and storage layouts • Retail layouts • Office layouts • Service layouts must be aesthetically pleasing as well as functional

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 equal time requirements.

37. Cycle Time Cycle time is the maximum time allowed at each workstation to complete its set of tasks on a unit.

38. Determine Maximum Output

39. Determine the Minimum Number of Workstations Required

40. Precedence Diagram 0.1 min. 1.0 min. A Simple Precedence Diagram a b c d e 0.7 min. 0.5 min. 0.2 min. Figure 6.11 Precedence diagram: Tool used in line balancing to display elemental tasks and sequence requirements

41. Example 1: Assembly Line Balancing • Arrange tasks shown in Figure 6.11 into three workstations. • Use a cycle time of 1.0 minute • Assign tasks in order of the most number of followers

42. Example 1 Solution

43. Calculate Percent Idle Time Efficiency = 1 – Percent idle time

44. Line Balancing Rules Some Heuristic (intuitive) Rules: • Assign tasks in order of most following tasks. • Count the number of tasks that follow • Assign tasks in order of greatest positional weight. • Positional weight is the sum of each task’s time and the times of all following tasks.

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

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

47. Bottleneck Workstation 30/hr. 30/hr. 30/hr. 30/hr. 1 min. 1 min. 2 min. 1 min. Bottleneck

48. Parallel Workstations 2 min. 30/hr. 30/hr. 60/hr. 60/hr. 1 min. 1 min. 1 min. Parallel Workstations 30/hr. 30/hr. 2 min.

49. Designing Process Layouts Information Requirements: • List of departments • Projection of work flows • Distance between locations • Amount of money to be invested • List of special considerations • Location of key utilities

50. Example 3: Interdepartmental Work Flows for Assigned Departments 30 170 100 1 2 3 A B C Figure 6.13