Design of Grated Coconut Roasting Machine through Ergonomic

Approach to Increase Work Productivity

Ketut Gde Juli Suarbawa and Ngurah Bagus Mulawarman

Mechanical Engineering Department, Bali State Polytechnic, Jalan Kampus Bukit Jimbaran, Kuta Selatan,

Badung, Bali, Indonesia

Keywords: Roasted Grated Coconut, Ergonomic Roast Machine, Work Productivity.

Abstract: In Karangasem Regency, roasted grated coconut is usually used as a way of kit for religious ceremonies.

Roasted grated coconut is traditionally made employing a gas range or burning stove with a production

capacity of about 1.5 kg of grated coconut. the typical daily production is around 6 kg, therefore the process

of roasting grated coconut is repeated. This roasting process is administered for a mean of 90 minutes for one

production. During the roasting process, the craftsmen stir the grated coconut continuously, and sometimes

because they feel tired, the stirring process gets slower in order that there are parts of the grated coconut that

get charred this causes the standard of the roasted grated coconut to be less good. In efforts to beat these

problems, a working mechanism is required with the assistance of a roasting machine, in order that it can

make it easier for craftsmen within the roasting process, reduce fatigue, reduce workload, and may increase

work productivity. For this reason, the planning of the roasting machine was administered through an

ergonomic approach in one short case study with a pre- and post-test design group which was administered

observationally on the roasting process manually and by employing a roasting machine. Ergonomic Roast

Machine specifications are designed with a capacity of 5 Kg as follows: a). The roasting tube may be a chrome

steel plate with a thickness of 1.2 mm with a length of 670 mm and a width of 310 mm, b). the facility of the

electrical motor is 0.25HP with a rotation of 1400 rpm while the rotation of the drum roast is 50 rpm with a

gearbox transmission, c). the size of the machine are 80 cm long, 75 cm wide and 90 cm high. Ergonomic test

results show that the utilization of a roasting machine can increase the work productivity of roasted grated

coconut craftsmen by 62.07%.

1 INTRODUCTION

The main problem within the roasting process of

grated coconut is an unnatural work posture, the work

process using hands as a piece tool and an extended

working time causing a rise in musculoskeletal

complaints, fatigue, and a rise in workload which

successively reduces work productivity, and long

working time. Adiputra, N. (2000) said that through

ergonomic intervention in small-scale industries

using ergonomic work equipment will reduce

workload and subjective complaints significantly

thereby increasing productivity. Pascale C, and

Shawna (2020) stated that the discipline of human

factors and ergonomics (HFE) can provide

approaches and methods to research and overcome

these challenges during systematic manners.

Ergonomics systems approach to explain some work

system barriers and facilitators experienced by

healthcare workers (Carayon P, Hundt AS, Karsh B-

T et al, 2006; Carayon P, Wetterneck TB, Rivera-

Rodriguez AJ et al, 2014)

Several alternative solutions to the issues above

through an ergonomic approach to the stirring

process, namely employing a roasting machine model

within the roasting process, are expected to scale back

workload, musculoskeletal complaints, and fatigue

levels also as shorten the working time and increase

work productivity. a piece posture that slows down

repeatedly for an extended time is non-physiological.

Work postures that aren't physiological are often

caused by the characteristics of task demands, work

tools, work stations, and work.

By designing the assembly process can save the

necessity for raw materials and processes, in order

that overall costs are often saved within the

manufacturing industry (Rusdiyantoro, 2011).

Increased pulse at work and complaints after work

Suarbawa, K. and Mulawarman, N.

Design of Grated Coconut Roasting Machine through Ergonomic Approach to Increase Work Productivity.

DOI: 10.5220/0010939400003260

In Proceedings of the 4th International Conference on Applied Science and Technology on Engineering Science (iCAST-ES 2021), pages 27-32

ISBN: 978-989-758-615-6; ISSN: 2975-8246

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

cause work productivity to be low (Manuaba, A.

2000). Work posture that's not physiological are often

caused by the characteristics of task demands, work

tools, work stations, and work Posture that are

incompatible with the skills and limitations of

workers (Kroemer and Grandjean, 2009; Manuaba,

A, 2000) Non-physiological work posture that's

administered for years can cause bone deformities in

workers (Kroemer and Grandjean,2009).

2 METHODOLOGY

2.1 Research Design

This research is a one-short case study with a pre and

post-test design group which was conducted

observationally on the working process of grated

coconut roasting (Corlett, Nigel, 2005; Nasution,

2012). The chart can be described as follows:

R P0 PI

Information:

R = Random sample.

P0= the result of the pre-test experimental unit.

PI = the result of the post-test experimental unit

Figure 1: Research Design.

2.2 Research Variable

The variables to be measured during this study

include: (1) workload as measured by the heart beat

of rice before and after work; (2) complaints of

fatigue and skeletal muscles before and after work;

(3) work productivity after work by comparing work

pulse (beats per minute) with the amount of products

produced (kg) during working time (minutes). The

measurement of variables number (1) to number (3)

is that the information data of the initial condition and

therefore the final condition which is then compared

to work out the comparison before using the roasting

machine and after using the roasting machine.

2.3 Data Analysis

The design data of the roasting a machine are

calculated supported the necessity for a load capacity

of 5 Kg, then an electrical motor, a shaft and a stirrer

tank, and an ergonomic machine holder construction

are planned. Test data before using roasting a

machine and after using roasting a machine include

data on working time/ a length of labour, a workload,

subjective complaints, and work productivity which

can then be analyzed descriptively to get conclusions.

3 RESULTS AND OUTCOMES

3.1 Manually Roasted Grated Coconut

Process

The process of creating roasted grated coconut on the

average takes about 3 hours from preparation to

completion. the typical working time of roasted

grated coconut craftsmen is around 6-7 hours per day

including lunch breaks for every week apart from

holidays / other major holidays or if there's no order.

They work from 9:00 a.m. to 5:00 p.m. Working

environment conditions with hot environmental

temperatures because of the influence of warmth

radiation from the furnace and solar heat radiation

always expose the workers although work is greatly

influenced by the working weather during a

comfortable working area, so it's not cold and not too

hot. Such a cushty temperature is around 24-26

C for

Indonesians (Suma’ mur PK, 2013). Thus, it's

assumed that the recent ambient temperature will

increase the workload of the workers making roasted

grated coconut. The working attitude of the roasted

grated coconut maker is by bending during a

squatting or standing position.

Figure 2: Craftsman Work Posture.

The position is a non-physiological work posture

and administered during a relatively long term and

plenty of overtime causes striated muscle strain

(reaction) and harms health (Manuaba, A, 2000).

Non-physiological work postures can be caused by

characteristics of task demands, work tools, work

stations, and work postures that are not in accordance

with the abilities and limitations of workers (Kroemer

and Grandjean, 2009), (Manuaba, A, 2000). Non-

iCAST-ES 2021 - International Conference on Applied Science and Technology on Engineering Science

physiological work posture carried out for years can

cause bone abnormalities for the workers (Kroemer

and Grandjean, 2019), and couse subjective disorder

of workers (suarbawa, at all, 2018),(Yusuf at all,

2017).

Likewise, the work attitude that accompanies

roasted grated coconut makers who are always in an

unnatural state will definitely cause disturbances to

the striated muscle system. Working continuously for

7-8 hours per day without being amid short breaks

will definitely end in the build-up of fatigue which

successively increases the workload. it's

characterized by a rise within the working pulse and

disturbances within the striated muscle system.

In a static working position that needs 50% of the

utmost force can't last quite one minute, if the force is

employed not up to 20% of the utmost strength then

the contraction will continue for a few time. As for

the duration of dynamic activity for 4 minutes or less

any individual can work with an intensity adequate to

aerobic capacity before resting (Kroemer and

Grandjean, 2009). Roles, et al. (2009) conducted a

study on work models supported ergonomics and

located that the work model was ready to reduce

fatigue up to 17.71%. Torik, et al. (2009) also stated

that the planning of an ergonomic work system can

reduce the extent of worker fatigue. The working

attitude of craftsmen should be cultivated in

physiological positions like when sitting and

standing, so as to not cause a forced attitude that

exceeds the physiological capabilities of the body

(Kroemer and Grandjean, 2009). Which is

ergonomically ready to reduce muscles skeletal

complaints of workers.

3.2 Roast Machine Design Model

The roasting machine is meant through an ergonomic

approach in order that the stress of the task with work

capacity should be during a balanced line in order that

high work performance is achieved. consistent with

Tarwaka (2004), the stress of labour assignments

shouldn't be too low and will not be too excessive

because both will cause stress.

The working rule of this coconut roasting machine

is that when the electrical motor is on, the pulley

which is one shaft with the electrical motor will

rotate. The rotation of the pulley will cause the

rotation of the pulley within the speed reducer

because it's connected by a v-belt. within the speed

reducer, the rotational speed coming from the

electrical motor are going to be reduced (reduced)

because the speed reducer contains a pair of gears.

Furthermore, the rotation are going to be transmitted

to the cylindrical axis of the roaster by a pair of gears

and chains. The horizontal cylinder (roast holder)

crammed with grated coconut rotates at low speed

and is heated by a heat source from LPG gas which is

channeled through holes within the heating pipe

located at rock bottom of the cylinder.

The results of the planning specifications for a 5

kg roasting machine are as follows: a). The roasting

tube may be a chrome steel plate with a thickness of

1.2 mm with a length of 670 mm and a width of 310

mm, b). the facility of the electrical motor is 0.25HP

with a rotation of 1400 rpm while the rotation of the

drum roast is 50 rpm with a gearbox transmission, c).

the size of the machine are 80 cm long, 75 cm wide

and 90 cm high.

Figure 3: Design of Coconut Roasting Machine.

Figure 4: The Result Coconut Roasting Machine.

Design of Grated Coconut Roasting Machine through Ergonomic Approach to Increase Work Productivity

3.3 The Result of Ergonomics Test

using Roasted Machine

3.3.1 Subjective Complaint

The working posture of the craftsman by sitting

hunched over causes a rise in musculoskeletal

complaints and complaints of fatigue because of the

bent attitude of the craftsmen amid exposure to

environmental heat because of radiation from the

stove/stove. A working posture that bends over and

over for an extended time may be a work posture

that's not physiological. Muscle complaints occur

because the muscles receive pressure because of

continuous workloads without relaxation (Bridge,

2005).

The results of measurements with a Nordic body

map questionnaire for 10 craftsmen who were

measured before and after work obtained the typical

difference between musculoskeletal disorders before

work and after work before treatment was 28.90 and

after treatment was 16.70. The decrease within the

mean difference between musculoskeletal disorders

before treatment and after treatment was significant

(p < 0.05) or 42.21%. This is in accordance with the

results of Habib's and Hojeij (2019) research on 504

bakery workers in Lebanon who were taken

randomly, showing that 23% of the workers at the

bakery reported experiencing upper extremity

complaints.

Table 1: Measurement Results of Musculoskeletal Disorder.

Descriptions

Everage difference

musculoskeletal

disorde

t p

Mean Standard

Deviation

Manual roasting

process

28,90 3,31

6,578 0,00

Machine roasting

process

16,70 4,30

3.3.2 Work Load

The average resting pulse of craftsmen within the

manual work process (before using the roasting

machine) is 69.84 (±2.31) bpm and therefore the

average working pulse is 105.96 (±1.46) bpm and

therefore the increase in work pulse is 37.53 (±2 .98)

bpm or 54.48%. the typical resting pulse of craftsmen

after employing a roasting machine is 68.43 (±1.71)

bpm and therefore the average working pulse is 97.08

(±2.00) bpm and a rise in work pulse is 27.24 (±1.64)

bpm or 39.00 %.

The average working pulse of the serundeng

maker before treatment was 105.96 (±1.46)

beats/minute including the category of medium

workload (Kimberly, 2011). This workload is caused

by workers working continuously without rest amid a

hot work environment because of heat radiation from

the furnace and solar heat radiation also as heat

radiation through the kitchen wall causing the

workload to extend.

Table 2: Resting Pulse, Pulse Working and Work Pulse.

Descriptions

Manual roasting

process

Machine

roasting process

t p

Mean SD Mean SD

Resting

Pulse

69.84 2.31 68.43 11.71 -1,53 0,16

Pulse

Working

105.96 1.46 97.08 2.00 10.51 0.00

Work Pulse 37.53 2.80 27.24 1.64 15.55 0.00

SD: Standard Deviation

3.3.3 Work Productivity

The work productivity of craftsmen within the roasted

grated coconut process is recorded supported the ratio

of output to input at a specific unit of time. The output

produced is that the amount of roasted grated coconut

(kilograms) produced by the crafted during working

hours, while the input is that the working pulse of the

crafted. The results of the calculation of productivity

after using the roasting machine is 152.69±3.37 while

before using the roasting machine it's 94.21±3.09 or a

rise of 62.07%. This increase in productivity is

because of a decrease in workload and an ergonomic

work attitude in order that fatigue and

musculoskeletal complaints are reduced and

production is increased. to extend productivity,

consistent with Kimberly (2011), it's necessary to

vary the work system to scale back the extent of

worker fatigue, in order that working time is shorter

and production can increase. Torik, et al. (2009) also

stated that the planning of an ergonomic work system

can reduce the extent of worker fatigue.

Table 3: Work Productivity of Craftsmen in The Roasted

Grated Coconut Process.

Descriptions n

Mini-

mum

Maxi-

mum

Mean

Standard

Deviation

Manual roasting

process

10 149 151 152.69 3.370

Machine

roasting process

10 91 102 94.21 3.091

Ergonomics intervention recommendations to extend

work productivity also are widely stated by

ergonomics researchers, like in Priambadi's research

iCAST-ES 2021 - International Conference on Applied Science and Technology on Engineering Science

(2012) through improving working conditions for a

smelting gamelan craftsmen can increase work

productivity by 26.67% and Bawa Susana's research

(2014) with ergonomics interventions can increase

work productivity 54.88%. Setiawan's research

(2016) through the work a station design can increase

work productivity by 20.29%

4 CONCLUSIONS

Based on the discussion that has been administered,

the subsequent conclusions can be:

1. The working posture of roasted grated coconut

craftsmen by sitting hunched over causes a rise in

musculoskeletal complaints and fatigue

complaints because of the craftsman's bending

work posture amid exposure to environmental

heat because of radiation from the stove/stove.

The working posture that bends over and over for

an extended time may be a work posture that's not

physiological.

2. The results of the planning of the roasted grated

coconut machine with a capacity specification of

5 Kg are as follows: a). The roasting tube may be

a chrome steel plate with a thickness of 1.2 mm

with a length of 670 mm and a width of 310 mm,

b). the facility of the electrical motor is 0.25HP

with a rotation of 1400 rpm while the rotation of

the drum roast is 50 rpm with a gearbox

transmission, c). the size of the machine are 80 cm

long, 75 cm wide and 90 cm high.

3. The results of testing the work productivity of

craftsmen through an ergonomic approach are

obtained that: a). the typical resting pulse of

roasted grated coconut craftsmen before using the

roasting machine was 69.84 (±2.31) bpm and

therefore the average working pulse was 105.96

(±1.46) bpm and therefore the increase in working

pulse was 37.53 (±2 .98) bpm or 54.48%. the

typical resting pulse of roasted grated coconut

craftsmen after employing a roasting machine is

68.43 (±1.71) bpm and therefore the average

working pulse is 97.08 (±2.00) bpm and a rise in

work pulse is 27.24 (±1.64) bpm or 39.00 %; b).

the typical difference between musculoskeletal

disorders before work and after work before

employing a roasting machine is 28.90 (±3.31)

and therefore the average difference between

striated muscle disorders before work and after

work after employing a roasting machine is 16.70

(±4.30). The decrease within the mean of striated

muscle disorders before using the roasting

machine and after using the roasting machine was

significant (p < 0.05) or 42.21%; and c). The

results of calculating the work productivity of

craftsmen before using the roasting machine is

94.21±3.09 and a rise after using the roasting

machine is 152.69±3.37 or a rise of 62.07%.

ACKNOWLEDGEMENTS

The authors would really like to thank the department

of research the community service center Bali State

Polytechnic and the Ministry of Education and

Culture of Indonesia for the financing of this research.

REFERENCES

Adiputra, N. (2000). Pulse and its Uses in Ergonomics.

Indonesian Journal of Ergonomics. Vol. 3 No. 1, June:

22-26

Bawa, S. I G. (2014). Ergonomic Hybrid Solar Dryer

Improves Worker Performance and Quality of Anchovy

in Banyubiru Jembrana Village. (Dissertation).

Denpasar. Udayana University Postgraduate Program.

Bridger, R.S. (2005). Introduction to Ergonomics.

Singapore: McGraw-Hill. (references).

Carayon P, Hundt AS, Karsh B-T et al. (2006). Work

system design for patient safety: the SEIPS model. Qual

Saf Health Care; 15:i 50-i8.

Carayon P, Wetterneck TB, Rivera-Rodriguez AJ et al.

(2014). Human factors systems approach to healthcare

quality and patient safety. Appl Ergon; 45:14–25.

Corlett, Nigel. (2005). Static Muscle Loading and the

Evaluation of Posture. Evaluation of Human Work, 3rd

Edition. London: Taylor & Francis. (references).

Habib, R.R., El-Harakeh, A. and Hojeij, S. (2019).

Musculoskeletal pain among bakery workers in

Lebanon: a national survey. Cogent Engineering. Vol.

6(1):1608-669.

I. K. G. J. Suarbawa, M. Arsawan, M. Yusuf, and I. M.

Anom Santiana, (2018). “Improvement of environment

and work posture through ergonomic approach to

increase productivity of balinese kepeng coin workers

in Kamasan village Klungkung Bali,” in Journal of

Physics: Conference Series

Kimberly, F.K. (2011). The Effect of Shift Work on Fatigue

of Palm Oil Mill Workers at PT. X Labuhan Batu.

Journal of Industrial Engineering, Vol. 12, No. 2,

August 2011. p110–117.

Kroemer and Grandjean, E. (2000). Fitting The Task To

The Human. A Texbook of Occupational Ergonomics

5th. Edition Philadelphie: Taylor and Francis.

(references).

Manuaba, A. (2000). Stress and Strain. Ergonomics. Vol.

II. Denpasar. Work Physiology Ergonomics Study

Program. Udayana University.

Design of Grated Coconut Roasting Machine through Ergonomic Approach to Increase Work Productivity

M. Yusuf, M. Santiana, and W. D. Lokantara, (2017).

“Improvement of work posture to decrease

musculoskeletal disorder and increase work

productivity jewelry worker in bali,” in Proceeding

International Joint Conferenceon Science and

Technology (IJCST) 2017, pp. 242–247.

Nasution, S. 2012. Metode Research (Scientific research).

. Jakarta: Bumi Aksara.

Pascale Carayon and Shawna Perry (2020). Human factors

and ergonomics systems approach to the COVID-19

healthcare crisis. International Journal for Quality in

Health Care, 2021, 33(S1), 1–3.

Priambadi, I G.N. (2012). Improving Working Conditions

of Bronze Alloy Smelting Improves the Performance of

Balinese Gamelan Craftsmen in Tihingan Village,

Klungkung. (Dissertation). Denpasar. Udayana

University Postgraduate Program.

Rolles P., Manuaba, A., Adiputra, N., Pangkahila, A.

(2000). Ergonomics (Apelerg) Based Field Practicum

Activity Model Improves Body Physiological

Response, Reduces Fatigue, and Increases

Performance, Compared to the Old Model (Apel), in

FMIPA Unima Students.

Rusdiyantoro, (2011), Product Green Design Development

to Support Green Lifecycle Engineering Manufactured

in Adibuana Metalworks, Prosiding International

Conference on Creative Industry (ICCI), ISBN 978-

979-781-8.

Setiawan, H. (2013). Ergonomically-based Wet Blanket

Work Station design improves the quality of life and

productivity of workers at PT Sunan Rubber

Palembang, South Sumatra Province. (Dissertation).

Denpasar. Udayana University Postgraduate Program.

Suma’mur PK. (2013). Company Hygiene and

Occupational Health (HIPERKES). Jakarta: Agung

Seto. (references).

Tarwaka,. (2010). Industrial Ergonomics: the basics of

ergonomics knowledge and workplace applications.

First Edition. Harapan Press Solo. ISBN

9789791814416. (references).

Torik, H., Kholil, M., Ari, S. (2009). Ergonomic Work

System Design To Reduce Fatigue Levels. Jurnal

Industrial and Systems Engineering Assessment

Journal (INASEA), Vol. 10 No.1, April 2009. p 45-58.

Indonesian Journal of Biomedical Sciences. Vol. 3, No.

1. January 2009.

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