Presented by:

Dr. Subhash Singh,

Assistant Professor

Manufacturing Engineering Department

National Institute of Technology Jamshedpur

Jamshedpur, Jharkhand, INDIA-831014

E-Mail:subh802004@gmail.com, subhash.prod@nitjsr.ac.in

Manufacturing Planning and Control

Production System

What is Production

Edwood Buffa defines production as ‘a process by which

goods and services are created’. Some examples of

production are: manufacturing custom-made products

like, boilers with a specific capacity, constructing flats,

some structural fabrication works for selected customers,

etc., and manufacturing standardized products like, car,

bus, motor cycle, radio, television, etc.

The production system is ‘that part of an organisation, which

produces products of an organisation. It is that activity whereby

resources, flowing within a defined system, are combined and

transformed in a controlled manner to add value in accordance

with the policies communicated by management’. A simplified

production system is shown below:

The production system has the following characteristics:

1. Production is an organized activity, so every production system

has an objective.

2. The system transforms the various inputs to useful outputs.

3. It does not operate in isolation from the other organisation

system.

4. There exists a feedback about the activities, which is essential to

control and improve system performance.

Classification of Production

Classification of Production

Job-Shop Production

Job-shop production are characterized by manufacturing one or few quantity of

products designed and produced as per the specification of customers within

prefixed time and cost. The distinguishing feature of this is low volume and high

variety of products.

A job-shop comprises of general-purpose machines arranged into different

departments. Each job demands unique technological requirements, demands

processing on machines in a certain sequence.

Job-shop Production is characterized by

1. High variety of products and low volume.

2. Use of general purpose machines and facilities.

3. Highly skilled operators who can take up each job as a challenge because of

uniqueness.

4. Large inventory of materials, tools, parts.

5. Detailed planning is essential for sequencing the requirements of each product,

capacities for each work centre and order priorities.

Advantages

Following are the advantages of Job-shop Production:

1. Because of general purpose machines and facilities variety of products can

be produced.

2. Operators will become more skilled and competent, as each job gives them

learning opportunities.

3. Full potential of operators can be utilized.

4. Opportunity exists for Creative methods and innovative ideas.

Limitations

Following are the limitations of Job-shop Production:

1. Higher cost due to frequent set up changes.

2. Higher level of inventory at all levels and hence higher inventory cost.

3. Production planning is complicated.

4. Larger space requirements.

Royce Royal Car Air Force One

Batch Production

American Production and Inventory Control Society (APICS) defines Batch

Production as a form of manufacturing in which the job pass through the functional

departments in lots or batches and each lot may have a different routing. It is

characterized by the manufacture of limited number of products produced at regular

intervals and stocked awaiting sales.

Batch Production is characterized by

1. Shorter production runs.

2. Plant and machinery are flexible.

3. Plant and machinery set up is used for the production of item in a batch and

change of set up is required for processing the next batch.

4. Manufacturing lead-time and cost are lower as compared to job order production.

Advantages

Following are the advantages of Batch Production:

1. Better utilization of plant and machinery.

2. Promotes functional specialization.

3. Cost per unit is lower as compared to job order production.

4. Lower investment in plant and machinery.

5. Flexibility to accommodate and process number of products.

6. Job satisfaction exists for operators.

Limitations

Following are the limitations of Batch Production:

1. Material handling is complex because of irregular and longer flows.

2. Production planning and control is complex.

3. Work in process inventory is higher compared to continuous production.

4. Higher set up costs due to frequent changes in set up.

Mass Production

Manufacture of discrete parts or assemblies using a continuous process are called

Mass Production. This production system is justified by very large volume of

production. The machines are arranged in a line or product layout. Product and

process standardization exists and all outputs follow the same path.

Mass Production is characterised by

1. Standardisation of product and process sequence.

2. Dedicated special purpose machines having higher production capacities and

output rates.

3. Large volume of products.

4. Shorter cycle time of production.

5. Lower in process inventory.

6. Perfectly balanced production lines.

7. Flow of materials, components and parts is continuous and without any back

tracking.

8. Production planning and control is easy.

9. Material handling can be completely automatic.

Advantages

Following are the advantages of Mass Production:

1. Higher rate of production with reduced cycle time.

2. Higher capacity utilization due to line balancing.

3. Less skilled operators are required.

4. Low process inventory.

5. Manufacturing cost per unit is low.

Limitations

Following are the limitations of Mass Production:

1. Breakdown of one machine will stop an entire production line.

2. Line layout needs major change with the changes in the product design.

3. High investment in production facilities.

4. The cycle time is determined by the slowest operation.

Continuous Production

Production facilities are arranged as per the sequence of production operations

from the first operations to the finished product. The items are made to flow

through the sequence of operations through material handling devices such as

conveyors, transfer devices, etc.

Continuous Production is characterized by

1. Dedicated plant and equipment with zero flexibility.

2. Material handling is fully automated.

3. Process follows a predetermined sequence of operations.

4. Component materials cannot be readily identified with final product.

5. Planning and scheduling is a routine action.

Advantages

Following are the advantages of Continuous Production:

1. Standardization of product and process sequence.

2. Higher rate of production with reduced cycle time.

3. Higher capacity utilization due to line balancing.

4. Manpower is not required for material handling as it is completely automatic.

5. Person with limited skills can be used on the production line.

6. Unit cost is lower due to high volume of production.

Limitations

Following are the limitations of Continuous Production:

1. Flexibility to accommodate and process number of products does not exist.

2. Very high investment for setting flow lines.

3. Product differentiation is limited.

Facility locationand Layout

Plant Location

Factors influencing location decision:

Factors influencing location decision:

Facility Layout

What is layout planning?

Layout planning is deciding the best physical arrangement of all resources

within a facility

• Facility resource arrangement can significantly affect productivity

• Two broad categories of operations:

o Intermittent processing systems – low volume of many different

products

o Continuous processing systems – high volume of a few

standardized products

Physical arrangement of equipment and facilities within a plant to ensure

a smooth flow of work, material, people and information

Plant Layout:

Plant layout refers to the arrangement of physical facilities such as

machinery, equipment, furniture etc. with in the factory building in such a

manner so as to have quickest flow of material at the lowest cost and with

the least amount of handling in processing the product from the receipt of

material to the shipment of the finished product.

Types of layout

It is long-term commitment

➢ It facilitates the production process, minimizes material handling,

time and cost, and allows flexibility of operations

➢ It facilitates easy production flow, makes economic use of the

building, promotes effective utilization of manpower, and provides

for employee’s convenience, safety, comfort at work, maximum

exposure to natural light and ventilation.

➢ It affects the flow of material and processes, labour efficiency,

supervision and control, use of space and expansion possibilities .

Types of layout

• Four basic layout types consisting of:

o Process or functional layout - Group similar resources together

o Product or line layout - Designed to produce a specific product

efficiently

o Hybrid or group layout - Combine aspects of both process and

product layouts

o Fixed-Position layouts - Product is two large to move; e.g. a

building

Process or functional layout

➢ In this type of layout machines of a similar type are arranged together

at one place. E.g. Machines performing drilling operations are

arranged in the drilling department, machines performing casting

operations be grouped in the casting department. Therefore the

machines are installed in the plants, which follow the process layout.

➢The work, which has to be done, is allocated to the machines

according to loading schedules with the object of ensuring that each

machine is fully loaded.

Typical Process or functional layout

➢Used when the operations system must handle a wide variety of

products in relatively small volumes (i.e., flexibility is necessary)

The grouping of machines according to the process has to be

done keeping in mind the following principles –

1. The distance between departments should be as short as

possible for avoiding long distance movement of materials.

2. The departments should be in sequence of operations

3. The arrangement should be convenient for inspection and

supervision

Advantages of Process or Functional Layout

1. Lower initial capital investment in machines and equipments. There is

high degree of machine utilization, as a machine is not blocked for a

single product.

2. The overhead costs are relatively low

3. Change in output design and volume can be more easily adapted to the

output of variety of products

4. Breakdown of one machine does not result in complete work stoppage

5. Supervision can be more effective and specialized

6. There is a greater flexibility of scope for expansion

Disadvantages of Process or Functional Layout

1. Material handling costs are high due to backtracking

2. More skilled labour is required resulting in higher cost.

3. Time gap or lag in production is higher

4. Work in progress inventory is high needing greater storage space

5. More frequent inspection is needed which results in costly

supervision

PRODUCT OR LINE LAYOUT

Under this, machines and equipments are arranged in one line

depending upon the sequence of operations required for the product.

The materials move from one workstation to another sequentially

without any backtracking or deviation. Under this, machines are

grouped in one sequence. Therefore materials are fed into the first

machine and finished goods travel automatically from machine to

machine, the output of one machine becoming input of the next.

For example in a paper mill, bamboos are fed into the machine at one end and

paper comes out at the other end. The raw material moves very fast from one

workstation to other stations with a minimum work in progress storage and material

handling.

The grouping of machines should be done keeping in mind the following general

principles.

a) All the machine tools or other items of equipments must be placed at the point

demanded by the sequence of operations.

b) There should no points where one line crossed another line.

c) All the operations including assembly, testing, packing must be included in the

line

Advantages of Product or Line Layout

1. Low cost of material handling, due to straight and short route and absence

of backtracking.

2. Smooth and uninterrupted operations

3. Continuous flow of work

4. Lesser investment in inventory and work in progress

5. Optimum use of floor space

6. Shorter processing time or quicker output

7. Less congestion of work in the process

8. Simple and effective inspection of work and simplified production control

9. Lower cost of manufacturing per unit

Disadvantages of Product or Line Layout

1. High initial capital investment in special purpose machine

2. Heavy overhead charges

3. Breakdown of one machine will hamper the whole production

process

4. Lesser flexibility as specially laid out for particular product.

Fixed Position or Location Layout

In this type of layout, the major product being produced is fixed at

one location. Equipment labour and components are moved to that

location rather than the product being moved through an assembly

line or set of assembly stations. . All facilities are brought and

arranged around one work center. This type of layout is not

relevant for small scale entrepreneur. E.g. - shipbuilding

Advantages of Fixed Position Layout

1. It saves time and cost involved on the movement of work from one

workstation to another.

2. The layout is flexible as change in job design and operation

sequence can be easily incorporated.

3. It is more economical when several orders in different stages of

progress are being executed simultaneously.

4. Adjustments can be made to meet shortage of materials or

absence of workers by changing the sequence of operations.

Disadvantages of Fixed Position Layout

1. Production period being very long, capital investment is very heavy.

2. Very large space is required for storage of material and equipment near the

product.

3. As several operations are often carried out simultaneously, there is

possibility of confusion and conflicts among different workgroups.

Hybrid or group layout

Certain manufacturing units may require all three processes namely

intermittent process (job shops), the continuous process (mass production

shops) and the representative process combined process.

In most of industries, only a product layout or process layout or fixed

location layout does not exist. Thus, in manufacturing concerns where

several products are produced in repeated numbers, Generally, a

combination of the product and process layout or other combination are

found in practice.

E.g. for industries involving the fabrication of parts and assembly,

fabrication tends to employ the process layout, while the assembly

areas often employ the product layout.

In soap, manufacturing plant, the machinery manufacturing soap is

arranged on the product line principle, but ancillary services such as

heating, the manufacturing of glycerin, the power house, the water

treatment plant etc. are arranged on a functional basis.