Human being is a characteristics species among all living species that distinguish itself from all other living species by its ability to magnify and extend its own capabilities. Earlier, the human being has been described as a tool utilizing other animals for carrying out the work generally ascribed by him for himself. The capabilities of man along with his desire for knowledge and improvement leads to the development of a device called “A machine”. A machine, as per one of the definitions given in ‘Oxford English Dictionary’ is “An apparatus for applying mechanical power consisting of a number of interrelated parts, each having a definite function.” The evolution of machine is attributed to the propagating power of machine which is inherited from its ancestor machines. Existing machine tool makes the pathway for the manufacturing of more advanced machine tools which successively serves to accelerate the evolution of new machine tools.
The industrial revolution which started in 18th century urges for mechanization by systematically eliminating human labour for the need of better work, consistence performance and higher production. The word mechanization was then replaced by the dynamic word “Automation”. The automation reinforces the process of technological development. Over a period of time, it has been seen that the machinery becomes more and more automated. This is achieved by eliminating machine-operator intervention in manufacturing processes and process controls. A high accuracy, consistence performance, greater production rate, etc. makes these machines inherently specialized. These specialized machines can process only limited number of components. The need of manually operated machines can been ruled out except for prototype and low volume component production.
Modern manufacturing systems and industrial robots are advanced automation systems that utilize computers as an integral part of their control. Computers are now a vital part of automation. They control stand-alone manufacturing systems, such as various machine tools, welders, and laser beam cutters. They run production lines and are beginning to take over control of an engine factory. Even more challenging are new robots performing various operations in industrial plants and participating in the full automation of factories.
It is well to keep in mind that the automatically controlled factory is nothing more than the latest development in the industrial revolution that began in Europe two centuries ago and progressed the following stages:
1. Construction of simple production machines and mechanizations started in 1770, at the beginning of the revolution.
2. Fixed automatic mechanism and transfer lines for mass production came along at the turn of this century. The transfer line is an organization of manufacturing facilities for faster output and shorter production time. The cycle of operation is simple and fixed and is designed to produce a certain product.
3. Next came machine tools with simple automatic control, such as plug board controllers to perform a fixed sequence of operations and copying machines in which a stylus moves on a master copy and simultaneously transmits command signals to servo drivers.
4. The introduction of numerical control (NC) in 1952 opened a new era in automation. NC is based on digital computer principles, which was a new technology at that time.
5. The logical extension of NC was computerized numerical control (CNC) for machines tools, in which a minicomputer is included as an integral part of the control cabinet.
7. Industrial robots were developed simultaneously with the CNC systems. The first commercial robot was developed in 1961, but they did not play a major role in the manufacturing until the late 1970s.
8. A fully automatic factory which employs a flexible manufacturing system (FMS) and computer and computer aided design/computer –aided manufacturing (CAD/CAM) techniques in the next logical extension. FMS means a facility that includes manufacturing cells, each cell containing a robot serving several CNC machines, and an automatic material- handling systems interfaced with a central computer.
Stages of development:
(i) First Industrial Revolution, began with the advent of powered machine tools and the creation of factories but continuously moved toward Mechanization rather labour muscle power.
(ii) Second Industrial Revolution, began in 1900s with advent of mass production and assembly lines. The large automated Material Mechanisms and transfer lines were developed. This type of automation is, these days, called as fixed automation. Specifically, Automation is a term was coined by D.S. Harder of Ford Motor company in 1947.
(iii) Third Industrial Revolution, evolved in recent years is flexible in contrast to second. In this, computers are used to control, processes as well as the information system i.e. both muscle as well as brain work for production.
Production is the a transformation process that converts raw material into finished products that have value in market place. The products are made by the combined efforts of man, machine, material and tools. All work requires both energy and information, and these two elements must be provided by some sources, either a human or any substitute. More the human attributes, if performed by a machine, the higher it has “automaticity”. Automaticy is thus defined as self-acting capability of the device in general terms.
Mechanization
Mechanization is providing human operators with machinery that assist them with the muscular requirements of work. It can also refer to the use of machines to replace human or animal labor. A step beyond mechanization is automation. Even the use of hand powered tools is an example of mechanization as it reduces the work of either screwing, drilling, inserting nails, punching or even power washing a surface.
Mechanical vs human labour
When we compare the efficiency of a labourer, we see that he has an efficiency of about 1%-5.5% (depending on whether he uses arms, or a combination of arms and legs).
Internal combustion engines have mostly about an efficiency of 20%. This although, some IC engines state efficiencies of <50%. Electrical engines have an efficiency of 90%, Hydrogen IC engines have an efficiency of 30%. Hydrogen fuel cell engines have an efficiency of 40-60%.
When we compare the costs of using an internal combustion engine to a worker to perform work, we notice that an engine can perform more work at a comparative cost. 1 liter of fossil fuel burnt with a IC engine equals about 50 hands of workers operating for 24 hours or 275 arms and legs for 24 hours.
In addition, the combined work capability of a human is also much lower than that of a machine. An average human can provide work good for around 250Wh/day, while a machine (depending on the type and size) can provide for far greater amounts of work. For example it takes four days of hard labour to deliver only one kWh - which a small engine could deliver in less than one hour while burning less than one litre of petroleum fuel. Combining both the inefficiency as well as the low cumulative work capability, we can see that a boss will pick a machine over a human anytime. This, as in practice it means that a gang of 20 to 40 men will require a financial compensation for their work at least equal to the required expended food calories (which is at least 4 to 20 times higher). In most situation, the worker will also want compensation for the lost time, which is easily 96 times greater per day. Even if we assume a the real wage cost for the human labour to be at US $1.00/day, an energy cost is generated of about $4.00/kWh. Despite this being a low wage for hard labour, even in some of the countries with the lowest wages, it represents an energy cost that is significantly more expensive than even exotic power sources such as solar photovoltaic panels (and thus even more expensive when compared to wind energy harvesters or luminescent solar concentrators).
mechanization provided human operators with machinery to assist them with the muscular
requirements of work
Automation
Automation means application of mechanical advantages, electrical amplification and computer processing etc. It guides the operations, maintenance, inspection with minimum use of humans. But it does not mean that automation leads to retrenchment. In fact, more jobs are created every year, than we eliminate with automation. Factory of future will have superior information system and simpler manufacturing processes/system. Hence, finally we conclude that,
Automation, is a technology in which the mechanical, electronic, computer based systems are used to operate and control production.
Or
Automation is a process which is carried out partly or fully according to a previously set programme, without the intervention of human activity for its operation or control.
Therefore, “Automation” implies that manual efforts should be replaced by mechanical, electrical machines and computers. Automation broadly includes following:
• Automatic Material Handling (MH) and Storage system.
• Automatic machine tools to process parts.
• Automated transfer and assembly lines.
• Industrial Robots.
• Automatic feedback for process control.
• Automatic inspection systems for quality control (QC).
• Computers for planning, designing, data collection and support decision making processes.
Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization, automation is a step beyond mechanization. Whereas mechanization provided human operators with machinery to assist them with the muscular requirements of work, automation greatly decreases the need for human sensory and mental requirements as well. Automation plays an increasingly important role in the world economy and in daily experience.
Automation has had a notable impact in a wide range of industries beyond manufacturing (where it began). Once-ubiquitous telephone operators have been replaced largely by automated telephone switchboards and answering machines. Medical processes such as primary screening in electrocardiography or radiography and laboratory analysis of human genes, sera, cells, and tissues are carried out at much greater speed and accuracy by automated systems. Automated teller machines have reduced the need for bank visits to obtain cash and carry out transactions. In general, automation has been responsible for the shift in the world economy from industrial jobs to service jobs in the 20th and 21st centuries.
Types of automation:
(i). Fixed/ Hard automation
(ii). Programmable automation
(iii). Flexible automation
Fixed Automation
A process using mechanized machinery to perform fixed and repetitive operations in order to produce a high volume of similar parts.
Characteristics:
• Justified/used where production rates/volumes are high.
• High initial investment for custom engineered equipment
• Normally cannot accommodate product changes.
• Depend largely on skill to organize thr operations.
• Produces large numbers of nearly identical parts
• Product design must be stable over its life
Advantages: equipment fine tuned to application - decreased cycle time, infrequent setups, automated material handling - fast and efficient movement of parts, very little WIP
Disadvantage: inflexible
Examples:
• Mechanized assembly lines.
• Mechanical lines.
Programmable Automation
In this type of automation, production machines, assembly lines are designed with the capability to change the sequence of operations to cater different types of product changes. This sequence is changed by set of instructions called program, for new products.
Characteristics:
• Sequence controlled by a program
• High investment in general purpose equipment
• Lower production rates
• Flexibility to deal with variation
• Suitable for batch production
• Smaller volumes (than fixed) of many different parts
• More flexible than fixed automation
• Major disadvantage: setup prior to each new part
• Large batch size (due to setups)
• Speed sacrificed for flexibility
Examples:
• Numerically controlled (NC) machines.
• Industrial robots
Flexible Automation
A flexible manufacturing system consists of a group of processing stations (CNC), interconnected by means of an automated material handling and storage system, and controlled by an integrated computer system.
Components of an FMS
1. Processing stations
2. Material handling and storage
3. Computer control system
Characteristics
• It is extension of programmable automation
• No time lost for change over
• High investment in custom-engineered systems
• Production of product mix
• Flexibility to deal with design variations
• Low to medium quantities
• Compromise between fixed and programmable automation in speed and flexibility
• Advantage: programming and setup performed off-line
• More expensive - size and tool change capabilities
• Small batch sizes are justified - reduced WIP and lead time
• Typical parts are expensive, large and require some complex machining
Examples:
• Use of pallet fixtures for holding parts.
• FMS (Flexible manufacturing systems)
• Automated Guided Vehicles (AGV) for material handling
Reasons for Automating
• Increase production rate
eliminate portions of process that directly increase production time: machine processing time, handling time, setup times (SMED)
• Remove humans from hazardous environments
exposure to chemicals, fumes, temperature or radiation
robotic applications: L/UL furnaces, spray painting, welding
• Remove humans from processes that require extremely clean environments: e.g., semiconductors, drugs
• Reduce number of defective products
• Reduce direct labor
one worker monitors a larger number of machine
• Increase production rate
• Strengths of (computer-based) machines
• Perform repetitive tasks consistently
• Store large amounts of data
• Retrieve data from memory reliably
• Perform multiple tasks simultaneously
• Apply high forces and power
• Perform computations quickly
Manual Labor in Automated Systems
Even if all of the manufacturing systems in the factory are automated, there will still be a need for the following kinds of work to be performed:
• Equipment maintenance. Maintain and repair, improve the reliability, of automated systems.
• Programming and computer operation.
• Engineering project work. Upgrades, design tooling, continuous improvement.
• Plant management.
Automation Principles and Strategies
There are ten Strategies for Automation
1. Specialization of operations.
2. Combined operations.
3. Simultaneous operations.
4. Integration of operations.
5. Increased flexibility.
6. Improved material handling and storage.
7. On line inspection.
8. Process control and optimization.
9. Plant operations control.
10. Computer integrated manufacturing (CIM).
Specialization of operations
Instead of general purpose, using special perpose equipment designed for greatest efficiency improves productivity and reduces operation time.
Combined operations
Since each machine involved in a sequence of operation requires a set-up. Hence, it can be tried to combine several operations on a single machine, therby reducing no. of machines; non operational time, material handling time. Doing more than one operations on a machine, reduces the no. of separate machines.
Simultaneous operations
In this strategy, two or more processing or assembly operations can be performed parallel on a single part at a single workstation. It reduces operation time.
Integration of operations
Linking of several workstations into single integrated mechanism by automated work handling equipment, increses overall output of the system.
Increased flexibility
Flexible automation attempts to achieve maximum utilization of equipment for job-order and medium volume production. It has lesser lead time, set-up time and work in process.
Improved material handling and storage
Material handling is the necessary non-productive time. Automated transfer machines reduce lead time, work in process, and non-operating time.
On line inspection
Automation also involves incorporating inspection within the manufacturing process as the product is being made, thereby reducing scrap and increasing quality of the product to required specifications.
Process control and optimization
A wide range of control scheme can be applied through automation for optimizing the each step of the process. It reduces operating time, scrap.
Plant operations control
Attempt to manage and control the operations at plant or aggregate level is made. Usually computer networking at the factory level helps in achieving lesser non productive time, lead time.
Computer integrated manufacturing (CIM)
Computer can also be used in design, CAD/CAM, CAPP (Computer Aided Process Planning) in addition to production and inventory database controls.
CIM is just an extension of CAD/CAM. The term CIM is coined to use the computers to:
(a) Design the product (CAD).
(b) Plan the production.
(c) Control the operations (FMS/CAM).
(d) Do business related functions.
Basically CIM is more concerned with information-processing functions required to support the production operations. CIM processes a wider meaning than CAD/CAM.
CIM has not only focused on the basic manufacturing system, but rather on how to use computers and robots to dirty work such as:
• Loading/unloading
• Line balancing
• Inventory control
• Process planning
• Using JIT (Just In Time) technology with manufacturing and assembly cell.
The purpose of CIM is to share information between Design, Engineering Manufacturing and the support departments such as sale/purpose and p[ersonnel department, thereby leading to factory of future.
Advantages
The main advantages of automation are:
• Replacing human operators in tasks that involve hard physical or monotonous work.
• Replacing humans in tasks done in dangerous environments (i.e. fire, space, volcanoes, nuclear facilities, underwater, etc.)
• Performing tasks that are beyond human capabilities of size, weight, speed, endurance, etc.
• Economy improvement. Automation may improve in economy of enterprises, society or most of humanity. For example, when an enterprise invests in automation, technology recovers its investment; or when a state or country increases its income due to automation like Germany or Japan in the 20th Century.
Disadvantages
The main disadvantages of automation are:
• Technology limits. Current technology is unable to automate all the desired tasks.
• Unpredictable development costs. The research and development cost of automating a process may exceed the cost saved by the automation itself.
• High initial cost. The automation of a new product or plant requires a huge initial investment in comparison with the unit cost of the product, although the cost of automation is spread in many product batches.
Relationship to unemployment
Most people consider it common sense that automation has the potential to foster unemployment, because it obviates human work by transferring tasks to machines. However, the translation of that potential into observed effect has largely not happened in the two centuries during which it has been continually predicted. After many decades of automation development and dissemination, the net macroeconomic effect has been generally positive—automation has been part of a general trend of economic growth worldwide; standards of living have risen in many places; and automation has never yet been shown to have induced any widespread structural unemployment. The main explanation for this is that, so far, job losses in any one particular economic niche have always been more than offset by job gains in other niches. As the lowered unit cost of goods and services (which the automation made possible) gave consumers more purchasing power to devote to other goods and services, new jobs sprang up in the production of those goods and services. Thus each time that automation has freed up human resources, those resources have been redeployed by market forces (although it did not always happen without turbulence in the lives of individual workers).
One of the earliest promises of automation was to allow more free time, without any threat of income reduction. This effect has been seen in many individual facets of life (for example, the automatic washing machine has made laundry less time-consuming; engine control units have reduced the amount of automotive downtime; the automatic dishwasher has made dishwashing less time-consuming), but the net outcome of modern life in developed economies remains a state of hurry and busyness, mostly because rising living standards have brought rising expectations in direct relation. (Each time-saving improvement has made room for a new aspiration to take its place.)
Automation also does not imply unemployment when it makes possible tasks that were unimaginable without it (such as exploring Mars with the Sojourner rover). Likewise with fields where the economy is already fully adapted to an automated technology, and the jobs were lost long enough ago that the displacement was long since absorbed by the workforce (as with the continually advancing automation of the telephone switchboard, which eliminated most telephone operator jobs and kept many more from ever existing in the first place).
Today automation is quite advanced (relative to just a few lifetimes ago), and it continues to advance with an accelerating pace throughout the world. Although it has been encroaching on ever more skilled jobs, the general well-being and quality of life of most people in the world (where political factors have not muddied the picture) have improved. Clearly a multivariate effect has been at work (something much more than just the obvious idea that automation has the potential to cause unemployment). In fact, the idea that automation posed an imminent threat to employment, first articulated in 1811 by a group of textile workers known as Luddites, has proven to be so fallacious over the ensuing two centuries that economists call the imminent-threat idea the Luddite fallacy. Today the eternal fallaciousness of the Luddite premise is a mostly undisputed principle of economic theory, because it has proven true empirically time and again.
There is some concern today that the economy's ability to continue absorbing ever-increasing automation without experiencing significant structural unemployment may be heading toward an upper limit—that is, that we are approaching a point where the Luddite premise will no longer be entirely fallacious, because the relationship of humans to machines that made it fallacious is changing. In this view, the empirical strength of the eternal-fallaciousness idea is only a reflection of the parameter values of the environment thus far. In other words, the idea is undoubtedly an excellent explanation of the past, but whether it can accurately predict the future is an independent problem. Like an investment prospectus, proponents of this view caution that "past performance is no guarantee of future results."
References:
Automation, Production systems, and Computer Integrated manufacturing by Groover
CAD/CAM by Groover, Zimmers
CAD/CAM/CIM by P. Radhakrisnan, S. Subramanyan, V. Raju
Computer Control of manufacturing System by Koren
Computer aided manufacturing by J. S. Narang
Computer aided manufacturing by R. K. Shrivastava
Automation and Robotics by R. K. Rajput
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