FREE ESSAY ON FACILITY LAYOUT

FACILITY LAYOUT

Chapter 6
Facility Layout
Facility layout refers to the configuration of departments, employee workstations,
customer service areas, material storage areas, restrooms, offices, computer rooms, and
for the flow patterns of materials and people around into and within buildings.
As process planning and facility layout planning proceed, there is a continuous
interchange of information between these two planning activities, because each affects
the other.
In operations strategy, the mix of competitive priorities that operation function can
provide is: low production costs, fast and on-time deliveries, high-quality products and
services, and product and volume flexibility. 
The objectives that drive facility layouts must reflect an appropriate mix of these
competitive priorities. Operations strategy drives facility planning, and facility
layouts serve as a means of achieving operations strategy.
( I ) BASIC LAYOUT TYPES
The central focus of most manufacturing layouts is to minimize the cost of processing,
transporting, and storing materials throughout the production system.
Materials Handling System: is the entire network of transportation that receives
materials, stores materials in inventories, moves them between processing points within
and between buildings, and finally deposits the finished products into vehicles that will
deliver them to customers.
The following describes the different types of layout:
1. Process Layouts (functional layouts, or job shops) 
Process layouts are the layouts that can handle varied processing requirements. They are
designed to accommodate variety in product and processing steps. They are also called
functional layouts, or job shops.
If a manufacturing facility produces a variety of custom products in relatively small
batches, the facility probably will use a process layout.
They use general-purpose machines that can be changed over rapidly to new operations for
different product design. These machines are usually arranged according to the type of
the process being performed.
2. Product Layouts 
Product layouts are layouts that use standardized processing operations to achieve
smooth, rapid, high-volume flow. They are designed to accommodate only a few product
designs. Such layouts are designed to allow a direct material flow through the facility
for products.
They use specialized machines that are set up once to perform a specific operation for a
long period of time on one product. These machines are usually arranged into product
department. Product layouts can take one of the following three forms:
a) Production Line; which is a standardized layout arranged according to a fixed sequence
of production tasks.
b) Assembly Line; which is a standardized layout arranged according to a fixed sequence
of assembly tasks.
c) U-Shaped Layout; is a compact layout requiring half the length of a straight
production line.
3. Fixed-Position Layouts
Fixed-Position Layouts are layouts in which the product or project remains stationary
(fixed position) and workers, materials, equipments are moved as needed.
* RELATED CONCEPTS
- Combination Layouts (Hybrid Layouts)
Most manufacturing facilities use a combination of the three layout types, where the
departments are arranged according to the types of processes but the products flow
through on a product layout. 
- Cellular Manufacturing (CM) Layouts 
Machines are grouped into cells; each cell is formed to produce a single parts family,
which require the same machines.
The flow of parts tends to be more like a product layout than a job shop.
- Group Technology
Group Technology refers to the grouping into part families of items with similar design
or manufacturing characteristics. 
- Flexible Manufacturing Systems (FMS)
Refers to chapter 5.
* Other Service Layouts
There are three layouts found in service environments, they are:
1. Warehouse and Storage Layouts.
2. Retail Layouts.
3. Office Layouts.
( II ) ANALYZING MANUFACTURING FACILITY LAYOUTS
Planning Product Layout
The analysis of production lines is the central focus of the analysis of product layouts.
The product design and the market demand for products determine the technological process
steps and the required production capacity of production lines. 
The number of workers, attended and unattended machines, and tools required to provide
the market demand must then be determined. This information is provided by line
balancing.
Line-Balancing
It is the analysis of production that nearly equally divides the work to be done among
work stations so that the number of workstations required on the production line is
minimized.
The goal of analysis of production line is to determine how many work stations to have
and which tasks to assign to each work station so that the minimum number of workers and
the minimum amount of machines are used to provide the required amount of capacity.
Line-Balancing Heuristics
They are methods based on simple rules that have been used to develop good solutions for
the problems aroused from the line balancing method. They are of two types; incremental
utilization heuristic, and longest task-time heuristic.
a) Incremental Utilization Heuristic
It is also called Maximum Utilization Rate (MUTR). This method simply adds tasks to a
workstation in order of task precedence one at a time until utilization is 100% or is
observed to fall. Then this procedure is repeated at the next workstation for the
remaining tasks. If a choice must be made between two or more tasks, the one with the
smallest task time is added.
The condition to which this method is perfectly applied is when task times are equal to
or greater than the cycle time.
However, this method creates the need for extra tools and equipment. But if the primary
focus of this method were to minimize the number of workstations or if the tools and
equipment used in the production line are either plentiful or inexpensive, then this
method would be appropriate.
* General Formulas to be used in the line-balancing methods:
or 
Problem1:
If you have the following data:
Tasks A B C D E F G H I
Time in Mts. 0.69 0.55 0.21 0.59 0.70 1.1 0.75 0.43 0.29
Predecessors - A B B B B C,D,E G,F H
- The demand rate per hour is 300 units, and the productive time per hour is 50 minutes.
a) Construct a sequence diagram.
b) Construct a production line, and evaluate.
Solution:
1. Construct the sequence diagram as follows:
2. Compute Cycle time as follows:
Cycle time = =0.167 minutes per units.
Since all task times are greater than cycle time, we will use the MUTR method.
3. Assign tasks to work centers as follows:
Work center Tasks Task Time Total Time Theoretical no of w.st.* Actual no of w.st.
U.T.R.
1 AA,BA,B,CA,B,C,D 0.690.550.210.59 0.691.241.452.04 4.147.448.712.24 58913
83%93%96.7%94.1%
2 DD,ED,E,F 0.590.701.1 0.591.292.39 3.57.714.3 4815 88.5%96.7%95.3%
3 FF,G 1.10.75 1.11.85 6.5911.1 712 94.1%92.5%
4 GG,H 0.750.43 0.751.18 4.57.1 58 90%88.75%
5 HH,I 0.430.29 0.430.72 2.574.3 35 85.2%86%
* Theoretical no of work stations = Total time/Cycle time
4. Construct a production line as follows:
Work Center 1 2 3 4 5 
Tasks A,B,C D,E F G H,I 
Theoretical no. of w.st. 8.7 7.7 6.6 4.5 4.3 31.2 Total
Actual no. of w.st. 9 8 7 5 5 34 Total
5. Evaluate using the U.T.R.
U.T.R. = = 92%
b) Longest Task-Time Heuristic
This method (LTT) adds tasks to a workstation one at a time in the order of task
precedence. If a choice must be made between two or more tasks, the one with the longest
task time is added. 
In this method there will be no duplicate of workstations, so the amount of tools and
equipment required is low, however this will reduce flexibility.
The condition to which this method is perfectly applied is when one or more is equal to
or less than the cycle time.
Problem2:
Solve problem 1 if the demand rate per hour is 40 units.
Solution:
1. Construct the sequence diagram as follows:
2. Compute Cycle time as follows:
Cycle time = =1.25 minutes per product.
Since all task times are less than cycle time, we will use the LTT method.
3. Assign tasks to work centers as follows:
Work Station Candidate Task Assigned Task Total Assigned Task Unassigned Time
Task Time 
1 AB AB 0.690.55 0.691.24 0.560.01
2 C,D,E,F F 1.1 1.1 0.15
3 C,D,E EC 0.700.21 0.700.91 0.550.34
4 D D 0.59 0.59 0.06
5 GH GH 0.750.43 0.751.18 0.500.17
6 I I 0.29 0.29 0.96
4. Construct a production line as follows:
Work Station 1 2 3 4 5 6 
Tasks A,B F E,C D G,H I 
Assigned time 1.24 1.1 0.91 0.59 1.18 0.29 5.31 Total
5. Evaluate using the U.T.R.
U.T.R. = = 88.5%