Presentation Transcript
Slide1: Operations Management Chapter 9 – Layout Strategy © 2006 Prentice Hall, Inc.
Innovations at McDonald’s: Innovations at McDonald’s Indoor seating (1950s)
Drive-through window (1970s)
Adding breakfast to the menu (1980s)
Adding play areas (1990s) Three out of the four are layout decisions!
Strategic Importance of Layout Decisions: Strategic Importance of Layout Decisions The objective of layout strategy is to develop an economic layout that will meet the firm’s competitive requirements
Layout Design Considerations: Layout Design Considerations Higher utilization of space, equipment, and people
Improved flow of information, materials, or people
Improved employee morale and safer working conditions
Improved customer/client interaction
Flexibility
Types of Layout: Types of Layout Office layout
Retail layout
Warehouse layout
Fixed-position layout
Process-oriented layout
Work cell layout
Product-oriented layout
Types of Layout: Types of Layout Office layout - positions workers, their equipment, and spaces/offices to provide for movement of information
Retail layout - allocates shelf space and responds to customer behavior
Warehouse layout - addresses trade-offs between space and material handling
Types of Layout: Types of Layout Fixed-position layout - addresses the layout requirements of large, bulky projects such as ships and buildings
Process-oriented layout - deals with low-volume, high-variety production (also called job shop or intermittent production)
Types of Layout: Types of Layout Work cell layout - a special arrangement of machinery and equipment to focus on production of a single product or group of related products
Product-oriented layout - seeks the best personnel and machine utilizations in repetitive or continuous production
Good Layouts Consider: Good Layouts Consider Material handling equipment
Capacity and space requirements
Environment and aesthetics
Flows of information
Cost of moving between various work areas
Office Layout: Office Layout Grouping of workers, their equipment, and spaces to provide comfort, safety, and movement of information
Movement of information is main distinction
Typically in state of flux due to frequent technological changes
Relationship Chart: Relationship Chart Figure 9.1
Supermarket Retail Layout: Supermarket Retail Layout Objective is to maximize profitability per square foot of floor space
Sales and profitability vary directly with customer exposure
Things at the counter have the most exposure.
Store Layout: Store Layout Figure 9.2
Retail Slotting: Retail Slotting Manufacturers pay fees to retailers to get the retailers to display (slot) their product
Contributing factors
Limited shelf space
An increasing number of new products
Better information about sales through POS data collection
Closer control of inventory
Warehousing and Storage Layouts: Warehousing and Storage Layouts Objective is to optimize trade-offs between handling costs and costs associated with warehouse space
Maximize the total “cube” of the warehouse – utilize its full volume while maintaining low material handling costs
More location than layout decision.
Cross-Docking: Cross-Docking Materials are moved directly from receiving to shipping and are not placed in storage in the warehouse
Requires tight scheduling and accurate shipments, typically with bar code identification
Fixed-Position Layout: Fixed-Position Layout Product remains in one place
Workers and equipment come to site
Complicating factors
Limited space at site
Different materials required at different stages of the project
Volume of materials needed is dynamic
Alternative Strategy: Alternative Strategy As much of the project as possible is completed off-site in a product-oriented facility
This can significantly improve efficiency but is only possible when multiple similar units need to be created
Process-Oriented Layout: Process-Oriented Layout Like machines and equipment are grouped together
Scheduling can be difficult and setup, material handling, and labor costs can be high
Process-Oriented Layout: Process-Oriented Layout Figure 9.3
Process-Oriented Layout: Process-Oriented Layout Arrange work centers so as to minimize the costs of material handling
Basic cost elements are
Number of loads (or people) moving between centers
Distance loads (or people) move between centers
Layout at Arnold Palmer Hospital: Layout at Arnold Palmer Hospital
Process-Oriented Layout: Process-Oriented Layout where n = total number of work centers or departments
i, j = individual departments
Xij = number of loads moved from department i to department j
Cij = cost to move a load between department i and department j
Process Layout Example: Process Layout Example Construct a “from-to matrix”
Determine the space requirements
Develop an initial schematic diagram
Determine the cost of this layout
Try to improve the layout
Prepare a detailed plan Arrange six departments in a factory to minimize the material handling costs. Each department is 20 x 20 feet and the building is 60 feet long and 40 feet wide.
Process Layout Example:
50 100 0 0 20
30 50 10 0
20 0 100
50 0
0
Process Layout Example Figure 9.4
Process Layout Example: Process Layout Example
Receiving Shipping Testing
Department Department Department
(4) (5) (6) Figure 9.5 Assembly Painting Machine Shop
Department Department Department
(1) (2) (3)
Process Layout Example: Process Layout Example Cost = $50 + $200 + $40
(1 and 2) (1 and 3) (1 and 6)
+ $30 + $50 + $10
(2 and 3) (2 and 4) (2 and 5)
+ $40 + $100 + $50
(3 and 4) (3 and 6) (4 and 5)
= $570
Process Layout Example: Process Layout Example Interdepartmental Flow Graph Figure 9.6
Process Layout Example: Process Layout Example Cost = $50 + $100 + $20
(1 and 2) (1 and 3) (1 and 6)
+ $60 + $50 + $10
(2 and 3) (2 and 4) (2 and 5)
+ $40 + $100 + $50
(3 and 4) (3 and 6) (4 and 5)
= $480
Process Layout Example: Process Layout Example Interdepartmental Flow Graph Figure 9.7
Process Layout Example: Process Layout Example
Receiving Shipping Testing
Department Department Department
(4) (5) (6) Figure 9.8 Painting Assembly Machine Shop
Department Department Department
(2) (1) (3)
Computer Software: Computer Software Graphical approach only works for small problems
Computer programs are available to solve bigger problems
CRAFT
ALDEP
CORELAP
Factory Flow
Work Cells: Work Cells Reorganizes people and machines into groups to focus on single products or product groups
Group technology identifies products that have similar characteristics for particular cells
Volume must justify cells
Cells can be reconfigured as designs or volume changes
Improving Layouts Using Work Cells: Improving Layouts Using Work Cells Current layout - straight lines make it hard to balance tasks because work may not be divided evenly Improved layout - in U shape, workers have better access. Four cross-trained workers were reduced. Figure 9.10 (b) U-shaped line may reduce employee movement and space requirements while enhancing communication, reducing the number of workers, and facilitating inspection
Requirements of Work Cells: Requirements of Work Cells Identification of families of products
A high level of training and flexibility on the part of employees
Either staff support or flexible, imaginative employees to establish work cells initially
Test (poka-yoke) at each station in the cell
Staffing and Balancing Work Cells: Staffing and Balancing Work Cells
Staffing Work Cells Example: Staffing Work Cells Example 600 Mirrors per day required
Mirror production scheduled for 8 hours per day
From a work balance chart
total operation time = 140 seconds
Staffing Work Cells Example: 600 Mirrors per day required
Mirror production scheduled for 8 hours per day
From a work balance chart
total operation time = 140 seconds Staffing Work Cells Example Takt time = (8 hrs x 60 mins) / 600 units
= .8 mins = 48 seconds
Work Balance Charts: Work Balance Charts Used for evaluating operation times in work cells
Can help identify bottleneck operations
Flexible, cross-trained employees can help address labor bottlenecks
Machine bottlenecks may require other approaches
Focused Work Center and Focused Factory: Focused Work Center and Focused Factory Focused Work Center
Identify a large family of similar products that have a large and stable demand
Moves production from a general-purpose, process-oriented facility to a large work cell
Focused Factory
A focused work cell in a separate facility
May be focused by product line, layout, quality, new product introduction, flexibility, or other requirements
Focused Work Center and Focused Factory: Focused Work Center and Focused Factory Table 9.2
Repetitive and Product-Oriented Layout: Repetitive and Product-Oriented Layout Volume is adequate for high equipment utilization
Product demand is stable enough to justify high investment in specialized equipment
Product is standardized or approaching a phase of life cycle that justifies investment
Supplies of raw materials and components are adequate and of uniform quality Organized around products or families of similar high-volume, low-variety products
Product-Oriented Layouts: Product-Oriented Layouts Fabrication line
Builds components on a series of machines
Machine-paced
Require mechanical or engineering changes to balance
Assembly line
Puts fabricated parts together at a series of workstations
Paced by work tasks
Balanced by moving tasks Both types of lines must be balanced so that the time to perform the work at each station is the same
Product-Oriented Layouts: Product-Oriented Layouts
Assembly-Line Balancing: Assembly-Line Balancing Objective is to minimize the imbalance between machines or personnel while meeting required output
Starts with the precedence relationships
Determine cycle time
Calculate theoretical minimum number of workstations
Balance the line by assigning specific tasks to workstations
Copier Example: Copier Example
Copier Example: Copier Example Figure 9.13
Copier Example: Copier Example 480 available mins per day
40 units required
Copier Example: Copier Example Line-Balancing Heuristics Table 9.4
Copier Example: Copier Example Figure 9.14
Copier Example: Copier Example