Facility Layout: Manufacturing and Services
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Transcript of Facility Layout: Manufacturing and Services
Facility Layout: Manufacturing and Services
Facility Layout
Facility layout means planning: for the location of all machines, utilities, employee
workstations, customer service areas, material storage areas, aisles, restrooms, lunchrooms, internal walls, offices, and computer rooms
for the flow patterns of materials and people around, into, and within buildings
Locate All Areas In and Around Buildings Equipment Work stations Material storage Rest/break areas Utilities Eating areas Aisles Offices
Characteristics of the Facility Layout Decision
Location of these various areas impacts the flow through the system.
The layout can affect productivity and costs generated by the system.
Layout alternatives are limited by the amount and type of space required for the various areas the amount and type of space available the operations strategy
Characteristics of the Facility Layout Decision
Layout decisions tend to be: Infrequent Expensive to implement Studied and evaluated
extensively Long-term commitments
Manufacturing Facility Layouts
Materials Handling The central focus of most manufacturing layouts is to minimize
the cost of processing, transporting, and storing materials throughout the production system.
Materials used in manufacturing include: Raw material Purchased components Work-in-progress Finished goods Packaging material Maintenance, repair, and operating supplies
Materials Handling
A materials-handling system is the entire network of transportation that:
Receives material Stores material in inventories Moves material between processing points Deposits the finished products into vehicles for delivery to customers
Materials Handling
Material-Handling Principles Move directly (no zigzagging/backtracking)
Minimize human effort required
Move heavy/bulky items the shortest distances
Minimize number of times same item is moved
MH systems should be flexible
Mobile equipment should carry full loads
Materials Handling
Material-Handling Equipment Automatic transfer devices Containers/pallets/hand carts Conveyors Cranes Elevators Pipelines Turntables
Basic Layout Forms Process Product Cellular Fixed-Position Hybrid
Process (Job Shop) Layouts Equipment that perform similar processes are grouped
together Used when the operations system must handle a wide
variety of products in relatively small volumes (i.e., flexibility is necessary)
Characteristics of Process Layouts General-purpose equipment is used Changeover is rapid Material flow is intermittent Material handling equipment is flexible Operators are highly skilled
Characteristics of Process Layouts Technical supervision is required Planning, scheduling and controlling functions are
challenging Production time is relatively long In-process inventory is relatively high
Product (Assembly Line) Layouts Operations are arranged in the sequence required to
make the product Used when the operations system must handle a
narrow variety of products in relatively high volumes Operations and personnel are dedicated to producing
one or a small number of products
Characteristics of Product Layouts Special-purpose equipment are used Changeover is expensive and lengthy Material flow approaches continuous Material handling equipment is fixed Operators need not be as skilled
Characteristics of Product Layouts Little direct supervision is required Planning, scheduling and controlling functions are
relatively straight-forward Production time for a unit is relatively short In-process inventory is relatively low
Cellular Manufacturing Layouts Operations required to produce a particular family
(group) of parts are arranged in the sequence required to make that family
Used when the operations system must handle a moderate variety of products in moderate volumes
Characteristics of Cellular ManufacturingRelative to Process Layouts Equipment can be less general-purpose Material handling costs are reduced Training periods for operators are shortened In-process inventory is lower Parts can be made faster and shipped more quickly
Characteristics of Cellular ManufacturingRelative to Product Layouts Equipment can be less special-purpose Changeovers are simplified Production is easier to automate
Fixed-Position Layouts Product remains in a fixed position, and the personnel,
material and equipment come to it Used when the product is very bulky, large, heavy or
fragile
Hybrid Layouts Actually, most manufacturing facilities use a
combination of layout types. An example of a hybrid layout is where departments
are arranged according to the types of processes but the products flow through on a product layout.
New Trends in Manufacturing Layouts Designed for quality Designed for flexibility - to quickly shift to different
product models or to different production rates Cellular layout within larger process layouts Automated material handling U-shaped production lines
New Trends in Manufacturing Layouts More open work areas with fewer walls, partitions, or
other obstacles Smaller and more compact factory layouts Less space provided for storage of inventories
throughout the layout
Planning Manufacturing Facility Layouts
Two Categories of Software Tools Computer aided design (CAD)
Allows 3-D, full-color views of facility design Allows virtual walk-throughs Ex. – ArchiCAD, AutoSketch, AutoCAD
Computer simulation Can simulate proposed system layout in operation and measure its
performance Ex. – ProModel, VisFactory, SIMPROCESS
Planning Manufacturing Facility Layouts Process and Warehouse Layouts Product Layouts Cellular Manufacturing Layouts
Planning Manufacturing Facility Layouts
Process Layouts Primary focus is on the efficient flow of materials The wide variety of potential product routings through the facility can
be evaluated using computer simulation
Warehouse Layouts Primary focus is the fast storage and retrieval of inventory items Decisions about aisle size/placement and location of each inventory
item can be evaluated using computer simulation
Planning Manufacturing Facility Layouts
Product Layouts Primary focus is on the analysis of production lines The goal of the production line analysis is to:
Determine how many workstations to have Determine which tasks to assign to which workstation Minimize the number of workers & machines used Provide the required amount of capacity
Line balancing is a key part of the analysis
Planning Product Layouts
Line Balancing Procedure1. Determine the tasks involved in completing 1 unit
2. Determine the order in which tasks must be done
3. Draw a precedence diagram
4. Estimate task times
5. Calculate the cycle time
6. Calculate the minimum number of workstations
7. Use a heuristic to assign tasks to workstations
Planning Product Layouts
Line Balancing Heuristics Heuristic methods, based on simple rules, have been
developed to provide good (not optimal) solutions to line balancing problems
Heuristic methods include: Incremental utilization (IU) method
Longest-task-time (LTT) method
… and many others
Planning Product Layouts
Incremental Utilization Method Add tasks to a workstation in order of task precedence one at a
time until utilization is 100% or is observed to fall Then the above procedure is repeated at the next workstation
for the remaining tasks Pro – Appropriate when one or more task times is equal to or
greater than the cycle time Con – Might create the need for extra equipment
Planning Product Layouts
Longest-Task-Time Method Adds tasks to a workstation one at a time in the order
of task precedence. If two or more tasks tie for order of precedence, the
one with the longest task time is added Conditions for its use:
No task time can be greater than the cycle time
There can be no duplicate workstations
Planning Product Layouts
Rebalancing a Production Line Changes that can lead to production lines being out of
balance or having insufficient/excess capacity are: Changes in demand
Machine modifications
Variations in employee learning and training
Planning Cellular Manufacturing Layouts Cell Formation Decision
Which machines are assigned to manufacturing cells
Which parts will be produced in each cell
Planning Cellular Manufacturing Layouts Fundamental Requirements for Parts to be Made in
Cells Demand for the parts must be high enough and stable enough that
moderate batch sizes of the parts can be produced periodically.
Parts must be capable of being grouped into parts families.
Planning Cellular Manufacturing Layouts
More-Complex Issues to be Resolved If all the parts cannot be cleanly divided between cells,
how will we decide which are to be the exceptional parts?
If inadequate capacity is available to produce all the parts in cells, which parts should be made outside the cells?
Planning Cellular Manufacturing Layouts
Cell Formation Procedure1. Form the Parts-Machines Matrix.2. Rearrange the Rows.
Place the machines that produce the same parts in adjacent rows.
3. Rearrange the Columns. Place the parts requiring the same machines in adjacent columns.
4. Use the rearranged parts-machines matrix to identify cells, the machines for that cell and the parts that will be produced in that cell.
Service Facility Layouts
Characteristics of Services There may be a diversity of services provided There are three dimensions to the type of service:
Standard or custom design Amount of customer contact Mix of physical goods and intangible services
There are three types of service operations: Quasi manufacturing Customer-as-participant Customer-as-product
Characteristics of Service Facility Layouts The encounter between the customer and the service
must be provided for. The degree to which customer-related features must
be provided varies with the amount of customer involvement and customer contact.
Planning Service Facility Layouts
Quasi-Manufacturing Services Several topics previously discussed under Manufacturing
Layouts are relevant here:Principles of material handling
CAD and simulation software
Line balancing
Planning Service Facility Layouts
Customer-as-Participant & Customer-as-Product An important element is providing for customer waiting lines
Amount of space needed for service counters and waiting customers
Placement of waiting lines in overall layout
Planning Service Facility Layouts For many service operations, layouts are like process
layouts in manufacturing The departments of hospitals are grouped and located
according to their processes In some cases, closeness ratings are used to reflect the
desirability of having one department near another
Wrap-Up: World-Class Practice Strive for flexibility in layouts
Multi-job training of workers
Sophisticated preventive-maintenance programs
Flexible machines
Empowered workers trained in problem solving
Layouts small and compact
Services follow the above practices plus incorporate customer needs in design