Thursday, 8 June 2006

Assembly Evolution (6/7)

The social advantages of assembly line work must be considered alongside the often serious psychological disadvantages. There can be a loss of job satisfaction when the worker is not involved in all of the assembly processes that lead to the finished product. The job is repetitive and some workers are unable to take much pride in the task itself, as they don’t have the opportunity of seeing how important their operation is to the successful completion of the product. Boring work may suppress the creative ability of the worker and their time out of work may be spent so passively that life goals may disappear. The effect of carrying out monotonous work is often excessive fatigue. With the decline in individual craftsmanship, many unskilled operatives have no opportunity to display their creative talent at work. Goods built on an assembly line lack the variety that can be created by craftsmen. This dull product uniformity can have an adverse effect on some workers who see the same product every 20 seconds or 1350 times a day.

Assembly lines are usually installed in factories with a large workforce. Each group within the factory is dependent upon the other for the manufacture of the product. Strike action by one group of workers may affect the production of the whole factory. The assembly worker output is effective only during the time spent doing tasks. The cycle time is fixed by the conveyor speed and so it is the periods of time spent off the job that reduce the output.

These psychological problems often cause the assembly worker to create avoidable delays in which they try to gain control of the rate of work.

The social effects of automation are different from those of the division of labour. Many of the simple operations carried out by assembly workers can be substituted with automatic workstations. By replacing workers with automation, these repetitive tasks are executed by machines. The displaced workers are then available to carry out other, less tedious, tasks like supervision and inspection. The automatic assembly machines must be fully utilised to be economically justified. Dedicated automatic assembly machines are less flexible than manual assembly lines. The products must be assembled in large batch sizes.  Overproduction and under-consumption lead to inefficiency.  Severe demand fluctuations and gross lack of demand can’t be accommodated with assembly automation.

Behavioural scientists say that technology can be applied to assembly without employing automation. They believe in job enlargement/enrichment and argue that the division of labour has been taken too far, to produce boring and repetitive assembly line jobs.

Job enlargement increases the number of tasks completed by a single operator and this is intended to give more interest and variety to the job. The same grade of worker does more complex operations.  The net effect of job enlargement is a reduction in the number of operators per assembly line, an increase the cycle time and more flexibility, but an overall increase in assembly costs.

No comments: