Ergonomics can help boost productivity

Dr. N. Yogaratnam

Ergonomics, though not familiar in the Sri Lankan scenario, is a multi-disciplinary science that strives to achieve higher productivity that will lead to increased profitability by understanding the capabilities and limitations of the workers.

Ergonomics is known as human factor engineering in USA and also known as psychological engineering in other parts of the world. The use of ergonomics is done in many fields, including astronautics, the design of aircraft and cars, and a wide variety of industrial process.

Ergonomics has been defined as “the scientific study of the relationship between man and his working environment with special reference to anatomical, physiological factors”. In this sense, the term environment is taken to cover not only the ambient environment in which he may work but also his tools and materials, his method of work and organization of his work, either as an individual or within a working group.

All these are related to the nature of the man himself; to his abilities, capacities and limitations. This also is considered as a branch of medicine which is concerned with human energy.

This has been also defined as the study of the psychological and physical factors that can be used to improve the design of both machines and system for human use.

The objective of ergonomics is to increase the efficiency of human activity by providing data which will enable informed decisions to be made. It should enable the cost to be minimized, in particular by removing those features of design which cause inefficiency or physical disability.

By its activities it should create an awareness in industry of the importance of considering human factors when planning work, thereby making a contribution not only to human welfare but to the national economy as a whole.

Taking plantations in Sri Lanka and India as test cases, this article explains how high productivity cannot be achieved if you ignore the human element.

Rubber tapping

Rubber plantations still remain vital to the economy of Sri Lanka. Rubber production in the country reached its peak level in 1978 at nearly, 155,000 metric tonnes. But although various factors contributed to a steady decline in production over the last several years, yet recently production picked-up again.

The total production in the year 2009 was 137 kg million a significant increase from 125 kg million. Further the average yields that have been achieved in the past by most of the estates in Sri Lanka have been in the region of 1000 - 1500 kg per hectare per year which is insufficient to maintain profitable operations. The estates should aim to achieve an average yield of 2,000 to 2,500 kg/hectare/year.

Tapping efficiency

Several yardsticks are available to the rubber industry for judging its production efficiency and its effect on cost reduction. Among them, the most important is tapping efficiency, which represents the quantity of latex harvested per man-day.

Even with good management, rubber fields similar in growth and yield pattern and plant density, substantial differences are recorded in the quantity of latex harvested by different tappers. These individual differences in tapping could be due to several factors.

One major factor is the effective tapping time i.e., the real time spent only on tapping and related activities, the next factor is the efficiency of the tapper or worker productivity which is based on physical capabilities, fitness of the tappers, social and environment factors.

Tapper productivity

Labour accounts for about 60 percent of the total cost of production of rubber in Sri Lanka. Tapping cost is a major component of cost of production and accounts for about 35 to 40 percent and about 70 percent of the worker’s time is spent on tapping.

Worker productivity measured in terms of Intake Per Tapper (IPT) is known to have a negative relationship on COP. In most plantations, the average intake per tapper for a given year varies from six to eight kg and the generally accepted norm is seven kg with a provision for an incentive payment for over kilos at the rate of about Rs 20.00 per kilo.

Human Factors

Human factors such as body weight, height, age, experience and anthropomorphic features (segmental weight of arm) have been found to influence tea plucker efficiency. It has also been reported that age of the plucker, length of the finger, segmental weight of the arm and number of children below six years had a negative relationship with tea plucker productivity in Sri Lanka.

It has also been found that length of arm, knowledge and skill, nutritional status, civil status and educational level also to be influencing tea plucker productivity. Similar worker related factors are expected to influence rubber tapper productivity as well.

Social aspects

Factors relating to health and nutrition of workers such as health care facilities, sanitation etc. are also known to influence worker productivity.

Health conditions such as anaemia, skin diseases, lung diseases, digestive disorders, paediatric disorders and defective eye sight are some of the known determinant of labour productivity in Plantations.

Household responsibilities of female workers with young children are also likely to adversely affect productivity.

Worker availability

Worker availability on estates is dependent on two main factors. The availability of workers who are willing to work in the estates and the frequency with which they report to work in the estates when work is offered.

There are clear indications that the availability of labour force, who may be resident or non-resident, cannot be taken for granted.

The overall labour deficit today has been the result of a slow but steady decline, averaging about four percent per year over the last ten years. The decline in labour is expected to continue in future. The situation is aggravated due to more attractive alternate work found by workers outside plantations.

Since rubber tapping is a skilled and labour intensive operation, declining labour force is a threatening factor.

Tapper requirement and availability

The total rubber extent in Sri Lanka is presently around 122,000 ha, out of which about 94,000 ha ie. 75 percent of the total extent are in production (tapping). With the mean mature stand of 500 trees/ha and a tapping task (no. of trees assigned per tapper) of 300-350 trees, the total tapper requirement of the country would be approximately 72,000. But under the present context, there is a shortage of skilled tappers which is in the region of 10 percent of the total requirement and a further 10 percent of available tappers are unskilled.

This is an unsatisfactory situation. Hence, there is an urgent need to look into tapper related problems in order to improve labour productivity, out turn and retention.

Time utilization

Tapping productivity may not only be affected by the factors already discussed, but also by time spent on tapping related activities.

Time utilization research, documents all activities of men, women and children from waking time to retiring time, whether paid or unpaid. This includes time taken for leisure, child care, sleep and so on.

In Sri Lanka the official working day for agricultural labour is eight hours, though this can vary in practice according to the nature of the task.

This does not normally include the time that is spent in travelling to and from work - it is time on the field. Effective time management is a major factor that would enhance tapping efficiency.

Selection of tappers

Tappers with experience, knowledge and developed skills on tapping and are regular to work are the most effective workers in terms of enhancement of productivity.

Human factors such as body height and weight, body mass index, and may be eye sight and nutritional anaemic conditions of the above workers unless they are extremely bad, need not be considered although health care facilities should be given priority as illness has been one of the major causes for absenteeism.

Enhancement of skilled tapper productivity and availability

In order to increase tapper productivity, estate profitability and minimize problems related to non-availability of skilled tappers, it may be possible to offer two tapping blocks of 300 trees/block to HITs on what may in future be referred to as “Normal Double Tapping”.

The effective tapping time under this system would be about 362 minutes which is still within their working time of 480 minutes/day.

Such tappers may be able to commence tapping at 6.00 a.m. and complete two blocks with a short leisure time of 30 minutes for snack at work site, to be provided by the estate. They may be provided with a battery operated lighting system if there is insufficient light for tapping and also a work uniform.

Skilled and knowledgeable tappers may be more effectively employed by assigning them tapping-only operation. Sundry workers acceptable to the tappers concerned can be used for other tapping related activities such as latex collection from 1200 trees (2 x 2 x 300 trees) and transportation by vehicle. This would save about 68 minutes of the productive time of the skilled tappers.

Management should ensure that there is no discrepancy between the actual latex intake and the weight indicated at the weighment point, which forms the basis for payment, as the latex is collected and transported by non-tapping sundry workers.

Loss of Recovery Double Tapping arrangement may be compensated by the introduction of “Rain-guarding” technology.

As the IPT is significantly different between panels, allocation of tapping fields on panels with high productivity to HITs is desirable.

Healthcare facilities should be given priority as illness is one of the major factor for absenteeism, which is negatively correlated with productivity.

The effective tapping time of 362 minutes is composed of 213 minutes of actual tapping operation time and 149 minutes of walking time from tree to tree. Management of walking time can be made more effective by altering the planting systems. This aspect, however, needs a careful and detailed study to avoid agronomic ineffectiveness due to competition for light, moisture and nutrients and may be higher incidences of pest and diseases.

Cost effectiveness of the proposed system of engagement of HITs

Engagement of HITs in the proposed manner would lead to an acceptable tapping cost of Rs 32.72 per Kg, while enhancing the earning capacity of the HITs. The tapping cost would include the wages of HITs, latex collection workers, cost of mid-day snack and cost of transport and uniform (Box 1).

Tapping skill and knowledge development programs

Emphasis should be placed on improved tapping skill in terms of angle, depth and length of tapping, in order to preserve the rubber tree and to assure steady income to tappers.

The HITs have taken 21 more minutes than LITs to complete the tapping task of 300 trees, but their standard in terms of length, depth and angle of tapping was superior to that of the LITs.

Unskilled, low intake tappers have to be identified and provided with specialized intensive training programs to upgrade them to the level of HITs. Such training programs should include both human related factors as well as technical aspects such as knowledge and tapping skills. This should be followed-up with regular impact monitoring, evaluation and reporting systems to provide regular feedback in order to identify critical issues and constraints and provide solutions to improve their performance.

Skill development plans should be drawn up regularly to educate and develop the tapping skills of the new generation of prospective tappers, as the present set of skilled tappers are in the category of 30 to 50 years of age. Although adequate knowledge and skill can be developed by working regularly and from parents, yet this may be further improved by means of systematic HRD programs for HITs also, as it is possible to increase their intake to over 15 kg level per 300 trees with improved human and technical strategies.

Incentives for new recruits (tapper-trainee)

In order to attract the younger generation, some incentives in the form of work uniform, snack at work site, change in designation, recognition of the training program completed by awarding certificates and may be and some cash prizes for merit performance should be offered.

Curriculum of G.C.E. (O/L) classes in schools in the rubber growing districts should include subjects that would provide some basic knowledge on rubber tapping, highlighting the importance and benefits of working as rubber tappers.

Women tea pluckers

The women workers bear a greater significance in plantation establishment and constitute about 52 percent of the labour force.

The tea plantation industry is seasonal and over 90 percent operations are carried in the fields.

To keep pace with production, especially plucking, more labour is required. The role of women is at forefront because they are deft in tasks related to tea plucking and other related tasks. The work is being performed in traditional way without knowing its impact on health.

Due to this backbreaking and drudgery prone work, the output of leisure of the worker decreases and the health is also affected. Thus, keeping in view the most neglected and essentially required aspect of women’s drudgery due to the tea plucking activity a study was designed in India, with the objectives:1. To study the socio-personal and physical characteristics of women engaged in tea plantation. 2. To determine the physiological workload of respondents engaged in tea plucking.

Majority of the respondents were married, illiterate and belonged to scheduled caste and other backward classes and followed a nuclear family with four to seven members in the family.

On an average, the respondents were employed for 12.28 years and earned the average monthly income of Rs 1,399.13 per month.

Majority of the workers had ectomorph body with average physical fitness level. The average working heart rate values were up to acceptable limits whereas, the peak heart rate values (HR25-35 - 110.93; 111.44; HR35-45 - 106.22, 110.58 beats/ min.) were beyond acceptable limits.

Both average and peak heart rate values were significantly related with elder age group, indicating work to be stressful especially with increase in age.

It was recommended to generate awareness regarding drudgery due to traditional working methods and faulty working habits must be imparted with the help of visits in tea farms and audiovisual aids, so as to enhance the work output and improve the health of women working in tea estates and to develop women friendly technologies to improve efficiency and output of women workers. Ergonomically designed light weight, hand-held, all-terrain harvester which is selective in that it harvests good quality flush, gives a 50 to 100 percent increase in worker output, reduces plucking costs, and maintains made-tea quality, and a plastic plucking baskets are recognized Sri Lankan innovations.

In conclusion, just as we refer to the aging plant population, it is now becoming necessary to monitor the not-so-well-known features of the aging worker population, both of which taken together, have an overlapping negative impact on the future levels of productivity and profitability in plantations.

Most nursery jobs are human-energy intensive, and this, coupled with the repetitive nature of many tasks, leads to substantial risk of repetitive-motion injuries. Tools to assist the workers by improving body posture and reducing the energy requirements of particular tasks have just begun to be developed.

This therefore, calls for a change in approach towards human factor in plantation management. Ergonomics is all about human resource management and little else.

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