Chapter 8
Benefits of product layout in job-shop kinds of production
1. Better human relations 2. Improved operator expertise 3. Less in-process inventory and material handling 4. Faster production setup
A good layout for face to face services
1. Easily understood service flow pattern 2. Adequate waiting facilities 3. Easy communication with customers 4. Easily maintained customer surveillance 5. Clear exit and entry points with adequate checkout capabilities 6. Departments and Processes arranged so that customers see only what you want them to see 7. Balance between waiting and service areas 8. Minimum walking and material movement 9. Lack of clutter 10. High sales volume per square foot of facility
Three steps shifting to a cellular layout
1. Grouping parts into families that follow a common sequence of steps 2. Identifying dominant flow patterns of parts families as a basis for a location of processes 3. Physically grouping machines and processes into cells
Balancing an assembly line, to reduce the longest task time below the required workstation cycle time
1. Split the task 2. Share the task 3. Use parallel workstations 4. Use a more skilled worker 5. Work overtime 6. Redesign 7. Upgrade equipment 8. Roaming helper to support the line 9. A change of materials 10. Multi-skilled workers operate as a team not independently
Marks of a good layout for manufacturing and back-office operations
1. straight line flow pattern 2. backtracking kept to a minimum 3. production time predictable 4. little interstage storage of materials 5. Open plant floors so everyone can see what is happening 6. Bottleneck operations under control 7. Workstations close together 8. Orderly handling and storage of materials 9. No unnecessary rehandling of materials 10. Easily adjustable to changing conditions
Assembly line balancing means
Assigning all necessary tasks to a series of workstations so that each workstation has no more than can be done in the workstation cycle time and so that idle (unassigned) time across all workstations is minimized
Ambient conditions
Background characteristics
Assembly line layout
Basic type of production layout formats is one in which equipment or work processes are arranged according to the progressive steps by which the product is made
Little
Having ________ interstage storage of materials is considered a good layout design for a manufacturing plant
Mixed-model line layout is used by
JIT manufacturers
Basic type of production layout format
Manufacturing fell
Ambient conditions examples
Noise level, music, lighting, temperature, scent
Reduced cost
Not a benefit of a manufacturing cell layout
Disposing of leftover Machinery and outsourcing I grouped processes
Not a step in developing a manufacturing cell layout
Speed up the assembly line transfer mechanism
Not a way to reduce the longest task time below the required workstation cycle time
Cost per square foot of alternative facilities
Not considered an input to the layout decision in facility layout analysis
Large team who collectively do a small part of a finished product
Not expect to see in a manufacturing cell layout
Systematic layout planning can be used in
Numerical flow of items between workcenters either is impractical to obtain or does not reveal the qualitative factors that may be crucial to the placement decision.
Retail service layout
Office layout is More akin to
Servicescape
Physical surroundings in which the service takes place and how these surroundings affect customers and employees
task ordering
Project layout, high degree of
task ordering
Project layout, high degree of ________ _______ is common
Inputs to the layout decision in facility layout analysis
Space requirements for the elements in the layout, specification of objectives and corresponding criteria to be used to evaluate the design, estimates of product or service demand on the system, processing requirements in terms of the number of operations and the flow between elements in the layout, space availability within the facility itself or if this is a new facility possible building configurations
The formats by which departments are arranged in a facility are defined by the general pattern flow
Three basic types (work center, assembly line, project layout), one hybrid (manufacturing cell)
Mixed-model line layout example
Toyota
line configuration
U-shape, straight, branching
A small team of workers who turn out compete units of work
What you expect to see in a manufacturing cell layout
Designing a production layout
a flexible line layout might have the shape of a "U"
Workcenter
a format in which similar equipment or functions are grouped together
straight-line flow pattern is considered
a good layout design for back-office service operations
Assembly line balancing, theoretical minimum number of workstations is found by
a ratio of the sum of all task times divided by the cycle time
Project layout is characterized by
a relatively low number of production units in comparison with workcenter and assembly-line formats
Assembly line balancing problem is one of
assigning all tasks to a series of workstations so that each workstation has no more that can be done in the workstation cycle time and so that the unassigned time across all workstations is minimized. problem is complicated by the relationships among tasks imposed by product design and process technologies
Material handling devices
belt or roller conveyor, over head crane
Manufacturing cell is similar to workcenter in that
cells are designed to perform a specific set of processes, similar to an assembly line that the cells are dedicated to a limited range of products
Manufacturing cell groups
dissimilar machines to work on products that have similar shapes and processing requirements
Purpose of assembly-line balancing, Cycle time is found by
dividing production time per day by the required units of output per day
Assembly line definition
equipment or work processes are arranged according to the progressive steps by which the product is made
length of the line
few or many workers
workstation cycle time
is not less than the time between successive units coming off the end of the line
assembly line layout
is similar to the basic production layout format of flow-shop layout
Manufacturing cell layout
is similar to the workcenter and assembly-line layouts
Differences among production layout flexible line layout
material handling devices, line configuration, pacing, product mix, workstation characteristics, length of the line
pacing
mechanical, human assembling
objective of a mixed- model line layout is to
meet the demand for a variety of products and avoid building high inventories
Assembly lines are
not a special case of a project layout
In a good layout design for a manufacturing facility
not acceptable to have backtracking by personnel in the delivery of a customer's product
Efficiency of an assembly line is
not found by a ratio of the sum of all task times divided by the cycle time
Project layout is
not similar to the basic production layout format of the workcenter
Systematic layout is
not used to design products
product mix
one product or multiple products
Assembly line refers to
progressive assembly linked by some material handling device
Assembly line product layout examples
shoes, chemical plants, car washes
Assembly lines are a
special case of product layout
Precedence relationship
specifies the order in which tasks must be performed in the assembly process
assembly line path is a
straight line
Workcenter layout is similar to
the basic production layout format of job-shop
Assembly line balancing procedure does not determine
the precedence relationships of manufacturing tasks
Workstation cycle time is the
time between successive units coming off the end of an assembly line
objective of a retail service layout is
to maximize net profit per square foot of store space
First step in balancing an assembly line is
to specify the precedence relationships among tasks to be performed on the line
workstation characteristics
workers may sit, stand, walk with the line or ride the line