Classification and Advantages of Plant Layout

Layouts can be classified into the following five categories:

1. Process layout.
2. Product layout
3. Combination layout
4. Fixed position layout
5. Group layout
Process Layout
Process layout is recommended for batch production. All machines performing similar type
of operations are grouped at one location in the process layout e.g., all lathes, milling
machines, etc. are grouped in the shop will be clustered in like groups.
Thus, in process layout the arrangement of facilities are grouped together according to their
functions. A typical process layout is shown in the following figure. The flow paths of
material through the facilities from one functional area to another vary from product to
product. Usually the paths are long and there will be possibility of backtracking.

Process layout is normally used when the production volume is not sufficient to justify a
product layout. Typically, job shops employ process layouts due to the variety of products
manufactured and their low production volumes.

Process layout

Advantages
1. In process layout machines are better utilized and fewer machines are
required.
2. Flexibility of equipment and personnel is possible in process layout.
3. Lower investment on account of comparatively less number of machines and
lower cost of general purpose machines.
4. Higher utilization of production facilities.
5. A high degree of flexibility with regards to work distribution to machineries
and workers.
6. The diversity of tasks and variety of job makes the job challenging and
interesting.
7. Supervisors will become highly knowledgeable about the functions under their
department.
Limitations
1. Backtracking and long movements may occur in the handling of materials
thus, reducing material handling efficiency.
2. Material handling cannot be mechanized which adds to cost.
3. Process time is prolonged which reduce the inventory turnover and increases
the in- process inventory.
4. Lowered productivity due to number of set-ups.
5. Throughput (time gap between in and out in the process) time is longer.
6. Space and capital are tied up by work-in-process.
Product Layout
In this type of layout, machines and auxiliary services are located according to the
processing sequence of the product. If the volume of production of one or more products is
large, the facilities can be arranged to achieve efficient flow of materials and lower cost per
unit. Special purpose machines are used which perform the required function quickly and
reliably.
The product layout is selected when the volume of production of a product is high such that
a separate production line to manufacture it can be justified. In a strict product layout,
machines are not shared by different products. Therefore, the production volume must be
sufficient to achieve satisfactory utilization of the equipment. A typical product layout is
shown in the following figure.

Product layout

Advantages
1. The flow of product will be smooth and logical in flow lines.
2. In-process inventory is less.
3. Throughput time is less.
4. Minimum material handling cost.
5. Simplified production, planning and control systems are possible.
6. Less space is occupied by work transit and for temporary storage.
7. Reduced material handling cost due to mechanised handling systems and
straight flow.
8. Perfect line balancing which eliminates bottlenecks and idle capacity.
9. Manufacturing cycle is short due to uninterrupted flow of materials.
10. Small amount of work-in-process inventory.
11. Unskilled workers can learn and manage the production.
Limitations
1. A breakdown of one machine in a product line may cause stoppages of
machines in the downstream of the line.
2. A change in product design may require major alterations in the layout.
3. The line output is decided by the bottleneck machine.
4. Comparatively high investment in equipments is required.
5. Lack of flexibility. A change in product may require the facility modification.

Combination Layout Advantages and Disadvantages

Combination Layout
A combination of process and product layouts combines the advantages of both types of
layouts. A combination layout is possible where an item is being made in different types
and sizes. Here machinery is arranged in a process layout but the process grouping is then
arranged in a sequence to manufacture various types and sizes of products. It is to be
noted that the sequence of operations remains same with the variety of products and sizes.
The following figure shows a combination type of layout for manufacturing different sized
gears.
Combination layout for making different types and sizes of gears
Fixed Position Layout
This is also called the project type of layout. In this type of layout, the material, or major
components remain in a fixed location and tools, machinery, men and other materials are
brought to this location. This type of layout is suitable when one or a few pieces of identical
heavy products are to be manufactured and when the assembly consists of large number of
heavy parts, the cost of transportation of these parts is very high.
Fixed position layout

Advantages
The major advantages of this type of layout are:
1. Helps in job enlargement and upgrades the skills of the operators.
2. The workers identify themselves with a product in which they take interest and
pride in doing the job.
3. Greater flexibility with this type of layout.
4. Layout capital investment is lower.
Group Layout (or Cellular Layout)
There is a trend now to bring an element of flexibility into manufacturing system as regards
to variation in batch sizes and sequence of operations. A grouping of equipment for
performing a sequence of operations on family of similar components or products has
become all the important.

Group technology layout in Operation Management

Group technology (GT) is the analysis and comparisons of items to group them into
families with similar characteristics. GT can be used to develop a hybrid between pure
process layout and pure flow line (product) layout. This technique is very useful for
companies that produce variety of parts in small batches to enable them to take advantage
and economics of flow line layout.

The application of group technology involves two basic steps; first step is to determine
component families or groups. The second step in applying group technology is to arrange
the plants equipment used to process a particular family of components. This represents
small plants within the plants. The group technology reduces production planning time for
jobs. It reduces the set-up time.

Thus group layout is a combination of the product layout and process layout. It combines
the advantages of both layout systems. If there are m-machines and n-components, in a
group layout (Group-Technology Layout), the M -machines and n -components will be
divided into number of machine-component cells (group) such that all the components
assigned to a cell are almost processed within that cell itself. Here, the objective is to
minimize the intercell movements.
The basic aim of a group technology layout is to identify families of components that
require similar of satisfying all the requirements of the machines are grouped into cells.
Each cell is capable of satisfying all the requirements of the component family assigned to
it.

The layout design process considers mostly a single objective while designing layouts. In
process layout, the objective is to minimize the total cost of materials handling. Because of
the nature of the layout, the cost of equipments will be the minimum in this type of layout. In
product layout, the cost of materials handling will be at the absolute minimum. But the cost
of equipments would not be at the minimum if the equipments are not fully utilized.

In-group technology layout, the objective is to minimize the sum of the cost of
transportation and the cost of equipments. So, this is called as multi-objective layout. A
typical process layout is shown .

Group layout or Cellular layout

Advantages of Group Technology Layout

Group Technology layout can increase
1. Component standardization and rationalization.
2. Reliability of estimates.
3. Effective machine operation and productivity.
4. Customer service.
It can decrease the

1. Paper work and overall production time.

2. Work-in-progress and work movement.
3. Overall cost.
Limitations of Group Technology Layout
This type of layout may not be feasible for all situations. If the product mix is completely
dissimilar, then we may not have meaningful cell formation.
Safety: It is a condition which gives you freedom from hazard, Risk and accident

Hazard: Anything which has potential to may cause harm

Risk: The likelihood that a hazard will cause harm in combination with the severity of injury, damage or
loss

Accident: An unplanned, unwanted event which leads to injury, damage or loss

Near miss: An unplanned, unwanted event that had the potential to lead to injury, damage or loss
but didn't

Welfare: Access to basic facilities such as hand wash station, Rest area, drinking water, toilet, and
First-Aid etc.

Why an organization has to manage health & safety

 Moral
Many people are killed, injured or made sick by their work. This is morally unacceptable, society
as a whole demands that people are safe whilst at work.
  Legal
Safe place of work, safe plant and equipment, safe system of work, Training supervision and
competency of staff
 Economics/Financial
Direct cost (Fines in the criminal court, First Aid treatment, worker sick pay, Compensation
payable to the victim, repairs to, or replacement of, damaged equipment, loss of
production/time etc.)
Indirect costs (Loss of staff from productive duties in order to investigate the incident, prepare
reports, undertake hospital visits, deal with relatives, attend court proceedings, loss of staff
morale, Damage to public image and business reputation, Damage to industrial relation, Loss of
goodwill of customers, General difficulties in training staff as an indirect result of the accident.

Carrying out Risk Assessment

5 Steps of risk assessment
1. Identify the hazards
2. Identify the people who might be harmed
3. Evaluate the risk and decide on precaution
4. Record the significant findings and implement them
5. Review and update as necessary

Risk Assessment of Task

 Select the task
 Record the steps or stages of the task
 Evaluate the risks associated with each step
 Develop the safe working method
 Implement the safe working method
 Monitor to insure it is effective

During Task development of a safe system of work

People:
What level of competence should they have? Vulnerable persons involved? Are there How
many people are working on the task?
Equipment:
What equipment will be used? What safety equipment will be required? What are the hazards
associated with the job and the equipment?
Materials:
What materials will be used or handled during the work? What are hazards of the materials?
How will waste be disposed of?
Environment:
In what type of environment will the work take place, e.g. space, light, and temperature? Might
any of these factors increase risk of need to be controlled?