Monday, 12 June 2006

Assembly Evolution (2/7)


Technology is the systematic knowledge of the industrial arts. Industrial engineers have been applying technology to the workplace for over two centuries. Manufacturing systems analysed by method and time studies have been improved by the division of labour, automation and robotics. Large productivity improvements have been achieved by applying technology to manufacturing processes. From the mechanisation of flour production to the robotic assembly of vehicles, process costs have been reduced. The application of technology to the motor industry has resulted in vast increases in productivity.

Method study is concerned with the dissection of a complex operation into it’s single constituent parts, which are then systematically analysed. The method study engineer synthesises the complete operation using components which optimise factors such as symmetry and the rhythm of movement.

The time study engineer measures the time taken to carry out an operation. The analysis is carried out in a systematic manner and it makes this form of study suitable only for simple and repetitive tasks. Often, time study exposes inefficient operations and these can then be analysed using method study.

It was the use of both method and time studies that led to the wide-scale use of the division of labour and the creation of the assembly line concept. Workers grouped on lines achieve productivity levels many times greater than single operatives making the entire product.

Automation has also produced large productivity increases by replacing men with machines. In highly automated manufacturing plants, the operator controls and supervises the process. The main power olders in future societies will not be capitalists or socialists, but people who possess expert technological skills. In this way, power will be passed to the techno-structure.


Automation in the manufacturing industries covers a whole range of electrical and mechanical equipment. In the field of automatic assembly, devices are used for automatic feeding and insertion. In addition, work transfer is by conveyor or rotating table. The type of system used for the assembly of a product is dependent upon many factors. The local cost of labour affects the economic justification of using automation to replace that labour. The frequency of design changes and the number of product styles dictate how flexible the equipment needs to be. The market life of the product influences the amortisation period of the capital investment. Finally, the annual product volume determines the required cycle time.

In addition to the above economic considerations, another reason for employing automatic assembly may be one of necessity. In certain areas, where labour is scarce, the use of automatic assembly is imperative. Certain operations may be hazardous or they must take place in dangerous working conditions. For example, the handling of toxic chemicals or working in extreme temperature conditions may exclude the use of manual workers. A further reason may be associated with the scheduling of the assembly operations: better control over production can be achieved with automation and product quality will be more consistent.

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