1. Process Selection and Facility Layout

2. Process types, process selection and automation

3. Process Selection The ways organizations choose to produce or
provide their goods and services.
It involves choice of technology, type of
processing, and so on.
It influences
Process selection refers to …. It has major implication For capacity planning, ….
The decision of process selection is made when new products or services are being planned. Process selection also occurs due to technological changes, as well as competitive pressure.
Capacity planning
Layout of facilities
Equipment
Design of work systems

4. Process Selection and System Design
Forecasting
Facilities and Equipment
Capacity Planning
Picture of system design.
(pointer) Capacity planning and process selection are based on ….,
Based on capacity planning and process selection, manager can choose what kind of facilities to build, what equipments to buy, how to design layout, and how to do work design.
Layout
Product & service Design
Process Selection
Work Design
Technological Change
Capacity is significantly impacted by process selection and facility layout.

5. Factors which influence process selection
Variety
How much
Flexibility
What degree
Volume
Expected output
Batch
Repetitive
Continuous
Job Shop
Project
To select an appropriate process, three primary questions should be answered.
How much variety in products or services will the system need to handle?
What degree of equipment flexibility will be needed?
What is the expected volume of output?

6. Process Types
Project: A non-repetitive set of activities directed toward a unique goal within a limited time frame
Unique
Examples: Building a bridge, consulting
Job shop: provides unit or lot production or service with changeable specifications, according to customer needs
Small scale
Examples: Machine shop, dentist’s office
Batch: Produces many different products in groups (batches)
Low or Moderate volume
Examples: Bakeries, movie theaters, classrooms
A job shop operates on a small scale. It is needed when a low volume of high-variety goods or services will be needed. Processing is intermittent.
Batch: moderate
Repetitive processing is used to produce high volumes of standardized goods or services.

7. Process Types (Cont.)
Repetitive: provides one or a few highly standardized products or services
High volumes of standardized goods or services
Examples: automobiles, computers, cafeteria, car wash
Continuous: produces highly uniform products or continuous services, often performed by machines
Very high volumes of non-discrete goods
Examples: refineries, chemical plant, flour, sugar, electricity supplying and the internet

8. Process Choice Affects Activities /Functions
Job Shop
Batch
Repetitive
Continuous
Projects
Cost estimation
Difficult
Somewhat routine
Routine
Simple to complex
Cost per unit
High
Moderate
Low
Very high
Equipment used
General purpose
Special purpose
Varied
Fixed costs
Variable costs
Very low
Labor skills
Low to high
Marketing
Promote capacities
Promote capacities; Semi-standard goods/ services
Promote standardized goods/ services
Scheduling
Complex
Moderately complex
Complex, subject to change
Work-in-process inventory

9. Automation
Automation: Machinery that has sensing and control devices that enables it to operate automatically
Standardized goods and services
Examples:
Goods: Automobile factories, semiconductors
Services: Package sorting, , on-line banking
A key question in process design is whether to automation.
Automation requires standardized goods and services.

10. Automation Types Fixed automation
Specialized equipment for a fixed sequence of operations
Programmable automation
Computer-aided design and manufacturing systems (CAD/CAM)
Numerically controlled (NC) machines: Machines that perform operations by following mathematical processing instructions.
Robot: A machine consisting of a mechanical arm, a power supply and a controller
Flexible automation
Manufacturing cell
Flexible manufacturing systems
Computer-integrated manufacturing (CIM)
Fixed automation uses specialized equipment for a fixed sequence of operations. Low cost and high volume are its primary advantages; minimal variety and the high cost of making major changes are its primary limitations. Programmable automation is at the opposite end. It involves the use of high-cost, general-purpose equipment controlled by computers. This type of automation can produce a wide variety of low-volume products in small batches. Flexible automation evolved from programmable automation. A key difference between the two is that flexible automation requires significantly less changeover time.

11. Flexible Manufacturing Systems
FMS are more fully automated versions of cellular manufacturing: A computer controls the transfer of parts from machine to machine as well as the start of work at each machine
Produce a variety of similar products

12. Classification of production systems and types of layouts

13. Facilities Layout
The arrangement of departments, work centers, and equipment, with particular emphasis on movement of work (customers or materials) through the system.

14. 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
Most common reasons for layout design include

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

16. Basic Layout Types
Product Layouts most helpful to repetitive processing
Process Layouts used for irregular processing
Fixed-position layouts used when projects require layouts
Hybrid layouts combinations of these above types
Cellular manufacturing
Group technology
Flexible Manufacturing Systems

17. Product Layouts
Product layout: Layout that uses standardized processing operations to achieve smooth, fast, high-volume flow
Made possible by highly standardized goods or services that allow highly standardized, repetitive processing
The work is divided into a series of standardized tasks, permitting specialization of equipment and division of labor
The large volumes handled by these systems usually make it economical to invest substantial sums of money in equipment and in job design.

18. Production/Assembly Line
Raw materials
or customer
Finished item
Station 2 3 4
Materials
and/or labor
Used for Repetitive or Continuous Processing
Example: automobile assembly lines, cafeteria serving line 1
In manufacturing environments

19. U-Shaped Production Line1 2 3 4 5 6 7 8 9 10 In
Out
Workers
Advantages:
… is more compact; its length is half the length of a straight line.
Communication among workers is increased because workers are clustered.
Compared to a straight line, flexibility in work assignments is increased because workers can handle more stations.
Materials entering point is the same as finished product leaving point, minimize material handling

20. Advantages of Product Layouts
High rate of output
Low unit cost
Labor specialization
Low material handling cost
High utilization of labor and equipment
Established routing and scheduling
Routine accounting, purchasing and inventory control
1. There is a high rate of output.
2. Units costs are low due to high volume; the high cost of specialized equipment is spread over many units.
3. Labor specialization reduces training costs and time and results in a wide span of supervision.
4. Material-handling costs are low per unit, and material handling is simplified because units follow the same sequence of operations.
5. There is a high utilization of labor and equipment.
6. Routing and scheduling are encompassed in the initial design of the system and do not require much attention once the system is in operation.
7. Accounting, purchasing, and inventory control are fairly routine.

21. Disadvantages of Product Layouts
Creates boring, repetitive jobs
Poorly skilled workers may not maintain equipment or quality of output
Fairly inflexible to changes in volume
Highly inclined to shutdowns
Needs preventive maintenance
Individual incentive plans are impractical
1. The intensive division of labor usually creates dull, repetitive jobs, which do not provide much opportunity for advancement and may lead to morale problems.
2. Poorly skilled workers may exhibit little interest in maintaining equipment or in quality of output.
3. The system is fairly inflexible in response to either changes in the volume of output or changes in product or process design.
4. The system is highly susceptible to shutdowns caused by equipment breakdowns or excessive absenteeism.
5. Preventive maintenance, the capacity for quick repairs, and spare parts inventories are necessary expenses.
6. Incentive plans tied to individual output are impractical since they would tend to cause variations among outputs of individual workers that would adversely affect high utilization of labor and equipment.

22. Process Layouts
Process layouts: Layouts that can handle various processing requirements
The layouts feature departments or other functional groupings in which similar kinds of activities are performed
Examples: Machine shops usually have separate departments for milling, grinding, drilling, and so on
Different products may present quite different processing requirements and sequences of operations

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

24. Comparison of Process and Product Layout

25. Advantages of Process Layouts
Can handle a variety of processing requirements
Not particularly at risk to equipment failures
Equipment used is less costly
Possible to use individual incentive plans
Systems can handle a variety of processing requirements.
The system is not particularly vulnerable to equipment failure.
3. General-purpose equipment is often less costly than the specialized equipment used in product layouts and is easier and less costly to maintain.
4. It is possible to use individual incentive systems.

26. 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, inventory control and purchasing are more involved
1. In-process inventory costs can be high if batch processing is used in manufacturing systems.
2. Routing and scheduling pose continual challenges.
3. Equipment utilization rates are low.
4. Material handling is slow and inefficient and more costly per unit than under product layouts.
5. Job complexities often reduce the span of supervision and result in higher supervisory costs than product layouts do.
6. Special attention for each product or customer (routing, scheduling, machine setups, and so on) and low volumes result in higher unit costs than with product layouts.
7. Accounting, inventory control, and purchasing are much more involved than under product layouts.

27. Fixed-Position Layouts
Fixed-Position Layout: Layout in which the product or project remains stationary, and workers, materials, and equipment are moved as needed
Examples:
Large construction projects (buildings, power plants, dams)
Shipbuilding, production of large aircraft
Rockets used to launch space missions
In fixed-position layouts, the item being worked on remains stationary, and workers, materials, and equipment are moved about as needed. This is in marked contrast to product and process layouts. Almost always, the nature of the product dictates this kind of arrangement: weight, size, bulk, or some other factor makes it undesirable or extremely difficult to attempt to move the product.

28. Combination Layouts
The three basic layout types may be altered to satisfy the needs of a particular situation
Examples:
Supermarket layouts: primarily process layout, have fixed-path material-handling devices as well (roller- type conveyors and belt-type conveyors)
Hospitals: process layout, fixed-position layout as well (patient care)
Off-line reworking (customized processing) of faulty parts in a product layout

29. 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
Design characteristics: size, shape and function.
Manufacturing or processing characteristics: type and sequence of operations required.
Some manufacturing are attempting to move away from process layouts in an effort to capture some benefits of product layouts. Ideally, a system would be flexible and be efficient with low unit production cost. Cellular manufacturing, group technology, and flexible manufacturing systems represent efforts to move toward this idea.
1. There are numerous benefits of cellular manufacturing. These relate to the grouping of equipment. They include
faster throughput time, less material handling, less work-in-process inventory, and reduced setup time.
2. For cellular manufacturing to be effective, there must be groups of items that have similar processing characteristics. Moreover, these items must be identified.
The grouping process is known as group technology and involves identifying items that have similarities in either design characteristics or manufacturing characteristics and grouping them into part families.

30. Line Balancing

31. 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.
Tasks are grouped into manageable bundles and assigned to workstations with one or two operators
Goal is to minimize idle time along the line, which leads to high utilization of labor and equipment
Perfect balance is often impossible to achieve

32. Cycle Time Cycle time is the maximum time allowed
at each workstation to complete its set
of tasks on a unit.
The primary determinant is what the line’s cycle time will be.
Cycle time also establishes the output rate of a line. For instance, if the cycle time is two minutes, units will come off the end of the line at the rate of one every two minutes.

33. Example 1: Cycle Times With 5 workstations, CT = 1.0 minute.
Cycle time of a system = longest processing time in a workstation.

34. Example 1: Cycle Times With 1 workstation, CT = 2.5 minutes.
Cycle time of workstation = total processing time in of tasks.
With 3 workstations, can CT = 1.0 minute?
0.5 min.
1.0 min.
0.7 min.
0.1 min.
0.2 min.
Workstation 1
Workstation 2
Workstation 3

35. Output Capacity OT Output capacity = CT OT = operating time per day
CT = cycle time
Example: 8 hours per day
OT = 8 x 60 = 480 minutes per day
Cycle Time = CT = 1.0 min
Output = OT/CT = 480/1.0 = 480 units per day
Cycle Time = CT = 2.5 min
Output = OT/CT = 480/2.5 = 192 units per day

36. Cycle Time Determined by Desired OutputOT D
CT = cycle time =
D = Desired output rate
Example: 8 hours per day
OT = 8 x 60 = 480 minutes per day
D = 480 units per day
CT = OT/D = 480/480 = 1.0 Minute

37. Theoretical Minimum Number of Stations Required
Nmin = CT å t =
sum of task times
Nmin = theoretical Minimum Number of
Workstations Required
Example: 8 hours per day, desired output rate is 480 units per day
CT = OT/D = 480/480 = 1.0 Minute
Nmin = ∑t /CT = 2.5/1.0 = 2.5 stations
≈ 3 stations

38. Designing Process Layouts

39. Designing Process Layout
The main issue in design of process layouts concerns the relative positioning of the departments involved.
Departments must be assigned to locations.
The problem is to develop a reasonably good layout; some combinations will be more desirable than others.

40. Considerations Some departments may benefit from adjacent locations
Sharing expensive tools or equipments.
Some departments should be separated
A lab with delicate equipment should not be located near a department that has equipment with strong vibrations.
Sand blasting department and painting department.
Flammable materials near a furnace.

41. Measures of Effectiveness
One advantage of process layouts: satisfy a variety of processing requirements
Customers or materials in these systems require different operations and different sequences of operations
One of the major objectives in process layout is to minimize transportation cost, distance, or time
This is usually accomplished by locating departments with relatively high interdepartmental work flow as close together as possible