1. Process Selection and Facility Layout

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

3. Process Selection and System Design
Outputs
Inputs
Forecasting
Product and Service Design
Technological Change
Capacity Planning
Process Selection
Facilities and Equipment
Layout
Work Design

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

5. Process Selection Batch Job Shop Repetitive Continuous Variety
How much
Flexibility
What degree
Volume
Expected output
Batch
Job Shop
Repetitive
Continuous
Batch = köteg

6. Process types
Downtime = állásidő

7. Process types and volume
Job shop
Small scale, wide variety of goods
Batch
Moderate volume, flexible
Repetitive or assembly line
High volumes of standardized goods or services
Continuous
Very high volumes of non-discrete goods
Projects
Non-routine work, unique set ob objectives, limited timeframe and resources

8. Product – Process Matrix
The diagonal of the matrix represents the ideal choice of processing system for a given set of circumstances.

9. Functions/activities affected by process choice
Job variety, process flexibility, unit cost
Volume
Limited (not ongoing)

10. Some examples (find the process type of each)
Movie production
Bakery
Restaurant (non fast food)
University
Car repairing (car mechanic shop)
Oil mining
Producing office tools
Veterinarian
Project
Batch
Job shop
Continuous
Repetitive

11. Product and service life cycles
Alongside the life cycle the sales and with it the production volume can change.
Thus managers must be aware of the change in the optimal processing system. (the necessity of change is highly dependent on the particular good or service)

12. Example
Computer building shop in a garage (working for order only, one computer at a time for given purposes)
The shop hires some workers and producing some dozens of computers for one customer at a time
Computer factory is established, creating large number of computer series
The R&D function of the firm invents a new computer prototype
Job shop
Batch
Repetitive
Project

13. Product/Service Profiling
Linking key product or service requirements to process capabilities.
Design the process with taking into consideration the following:
Range of products/services
Expected order size
Pricing
Expected frequency of changes in schedules etc.
Order-winning requirements …

14. Sustainable production
Non-polluting
Conserving natural resources & energy
Economically efficient
Safe and healthful for workers, communities and consumers
Socially and creaqtively rewarding for workers

15. Automation of production and services
Automation: Machinery that has sensing and control devices that enables it to operate
Fixed automation
Programmable automation

16. Advantages of automation
Low variability in performance and quality
Machines do not
get bored or distracted
go out on strike or ask for higher wages
lower variable costs

17. Disadvantages Higher initial (investment) cost and Higher fixed costs
Lower felxibility
Higher skills needed
Lower morale of human workforce
Need for standardisation
Products
Processes
Equipment and materials etc.

18. Automation Computer-aided design and manufacturing systems (CAD/CAM)
Numerically controlled (NC) machines
Computerized numerical control (CNC)
Direct numerical control (DNC)
Robot: mechanical arm + power supply + controller
Manufacturing cell
Flexible manufacturing systems (FMS)
Computer-integrated manufacturing (CIM)
Computer-integrated manufacturing (CIM): allows individual processes to exchange information with each other and initiate actions

19. Facilities Layout
Layout: the configuration of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system

20. 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

21. The Need for Layout Decisions
Inefficient operations
High (variable) cost
Bottlenecks
Changes in the design of products or services
The introduction of new products or services
Safety
Changes in environmental or other legal requirements
Changes in volume of output or mix of products
Changes in methods and equipment
Morale problems

22. Objectives of facility layout
Main: smooth flow of work, material and information Supporting objectives:

23. Basic Layout Types Product layouts Process layouts
Fixed-Position layout
Combination layouts:
Cellular layout (& group technology)
Flexible manufacturing systems

24. Basic Layout Types Product layout Process layout Fixed Position 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

25. Product Layout
Used for Repetitive or Continuous Processing

26. 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

27. 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

28. A U-Shaped Production Line

29. Advantages/disadvantages of U-shaped lines
Shorter distances for workers & machines
Permits communication thus facilitates teamwork
More flexible work assignments
Optimal if the facility has the same entry and exit point
If lines are highly automated, there is no need for communication and travel
If entry points are on the opposite side as exit points
Noise and contamination factors are increased in the U-shape

30. Used for Intermittent processing
Process Layout
Process Layout
(functional)
Dept. A
Dept. B
Dept. D
Dept. C
Dept. F
Dept. E
Intermittent = megszakításos
Used for Intermittent processing
Job Shop or Batch

31. 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

32. 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

33. Fixed-position layouts
The product or project remains stationary and workers, materials, and equipment are moved as needed.
If weight, size, bulk, or some other factor makes it undesirable or extremely difficult to move the product.
E.g. firefighting, road-building, home-building, drilling for oil etc.

34. Cellular Layouts Cellular Production Group Technology
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
Makes cellular production much more effective
Cellular = sejtszerű

35. Traditional process layout
Cellular layout
Traditional process layout
Milling = marás, deburring = csiszolás; boring = fúrás

36. Functional vs. Cellular Layouts
Dimension
Functional
Cellular
Number of moves between departments
many
few
Travel distances
longer
shorter
Travel paths
variable
fixed
Job waiting times
greater
Throughput time
higher
lower
Amount of work in process
Supervision difficulty
Scheduling complexity
Equipment utilization

37. Flexible manufacturing systems
FMS: a group of machnies designed to handle intermittent processing requirements and produce a variety of similar products.
CIM (Computer Integrated Manufacturing): a system of linking a broad range of manufacturing activities through an integrating computer system

38. Service Layouts Warehouse and storage layouts Retail layouts
Minimizing movement & picking time and cost
Retail layouts
Presence & influence of customers
Office layouts:
Information is computerized, image of openness

39. 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.
This way the idle time will be minimized, utilization will be maximized.
Specialization: dividing work into elemental tasks that can be performed quickly and routinely.

40. Cycle Time
Cycle time is the maximum time allowed at each workstation to complete its set of tasks on a unit.
tmax < Cycle time < ∑t

41. Determine the Minimum Number of Workstations Required
(rounded up to the next integer)
Theoretical Nmin is not necessarily will be the Nactual. The latter is affected by other technical and practical considerations, too. Nmin ≤ Nactual

42. A simplified precedence
Precedence Diagram
A diagram that shows elemental tasks and their precedence requirements.
A simplified precedence
diagram a b c d e
0.1 min.
0.7 min.
1.0 min.
0.5 min.
0.2 min.

43. Example 1: Assembly Line Balancing
Assume that the desired output is 480 units per day. The facility is working 8 hours a day. The elemental tasks and their connections are shown on the previous slide.
Calculate the cycle time.
Calculate the minimum number of workstations.
Arrange the tasks to these workstations in the order of the greatest number of following tasks.

44. Example 1 Solution Workstation Time Remaining Eligible Assign Task
Revised Time Remaining
Station Idle Time 1
1.0
0.9
0.2
a, c *
c **
none*** a c - 2 b
0.0 3
0.5
0.3 d e
Total: 0.5
Eligible = kiosztható
* Tasks that have no predecessors.
** b is not eligible, because it needs more time than than the remaining.
*** Every available task needs more time than 0.2.

45. Calculate Percent Idle Time and efficiency
Efficiency %= 100 x (1 – Percentage of idle time)

46. Line balancing procedure

47. Line Balancing Heuristics
Assign tasks in order of most following tasks.
Count the number of tasks that follow
Assign tasks in order of task time.
Assign tasks in order of greatest positional weight.
Positional weight is the sum of each task’s time plus the times of all following tasks.

48. Example 2
Working day is 8 hours and the desired output rate is 400 units per day.
Draw the precedence diagram.
Compute the cycle time & the minimum theoretical number of workstations required.
Assign tasks to workstations according to the greatest number of following tasks. Tiebreaker: longest processing time goes first.
Calculate Percent idle time & efficiency.

49. Solution 2 CT = (8*60)/400= 1.2; Nmin = ∑ti / CT = 3.17 → 4a b e c f d h g
CT = (8*60)/400= 1.2; Nmin = ∑ti / CT = 3.17 → 4
Work station
Tasks assigned
Idle time
WS1
a,c,b
WS2
d,e
0.3
WS3 f
0.2
WS4
g,h
0.5
Percentage idle time = 1.0 / (4*1.2) = 20.83%
Efficiency = 100 – = 79.17%

50. Other approaches Paralell workstations
Cross-train workers (dynamic line balancing)
Mixed model line (more product on the same line)

51. Parallel Workstations
1 min.
2 min.
30/hr.
1 min. on average
60/hr.
Bottleneck
Parallel Workstations
2 min.
2 min.

52. Thank you for your attention