Effect of quality of work life on job performance among power plant operators

The operators of the electrical power plants are among these population, who have irregular working schedules and perform the activities which are characterized by significant mental and

UNIVERSITY OF ECONOMICS HO CHI MINH CITY

International School of Business

UNIVERSITY OF ECONOMICS HO CHI MINH CITY

International School of Business

SUPERVISOR: PHAM NGOC THUY

Ho Chi Minh City – Year 2018

Introduction

Human resources are key firm resources (Tho, Phong, & Quan, 2014) Regarding people

at the workplace, quality of work life and the relationship between work and life have received much attention in comparison with the other areas by researchers in the last few years (Nguyen & Nguyen, 2012) This can be explained that “Quality of work life (QWL) has attracted academics as well as practitioners because it affects job performance and many other job factors (Lee et al., 2007; Sirgy et al 2001; Wright 2010), and ultimately the quality of life of employees (Nguyen and Nguyen 2012)” (as cited in Tho, 2018, p 461)

Walton (1973) argues that QWL is a term that represents environmental and human principles, but these are suspended because of the technological evolution and economic development And the most recent statistics indicate that the majority of the working population is engaged in irregular or non-standard working hours, including shift and night work, weekend work, split shifts (Costa, 2010) Costa (2010) explains that this issue is related to the development of new technologies and the extension of basic

services to general populations, requiring continuous human assistance and control over the work processes during the 24 hour day And this issue is also associated with the increasing economic competition among companies and countries, due to the progressive globalization of the labor market and productive strategies, which entail an increasingly intensive and extensive exploitation of productive systems

Peters, Engels, de Rijk, and Nijhuis, (2015, p 882) argue that “irregular work schedules and working hours warrant specific attention, because both are linked to a wide

range of negative consequences, e.g self-rated health, fatigue, work–home interference, job satisfaction, decline in performance, and sick leave” Hence, “improving adaptability necessarily implies a focus on the human operator, the center of the manufacturing

processes” and “human quality of work intersection with production system performance parameters, should be evaluated and optimized” (Layer, Karwowski, & Furr, 2009, p 414)

The operators of the electrical power plants are among these population, who have irregular working schedules and perform the activities which are characterized by

significant mental and psychosocial demands, such as the time pressure, responsibility, amount of work, problem solving, decision-making, the high level of concentration

required and adjustment to new technologies and have to carry it out by mobilizing

knowledge and reasoning to which they have adequate training under the terms of the existing rules (Silva, Marqueze, Rotenberg, Fischer, & Moreno, 2012)

The activities performed and services provided by the electric sector are essential

to the whole population, which is an important ingredient to the development of a

country, the electrical systems can be categorized as critical systems where failure can result in significant financial loss, injury or threats to human life For those power plant in which the operators who have capability of making decisions quickly and effectively can help the company to avoid fines and penalties by National Load Dispatch Center Hence,

in order to survive and to create sustainable growth and development, the power plants are required to have a new approach to management of the operators Thus, understanding factors that impact on operator performance and how these factors can influence operator

performance is paramount to effective management (Nguyen, Dang & Nguyen, 2015) In this sense, this study aim to evaluate the impacts of QWL on job performance among operators in power plants who have received little attention in Vietnam

Literature review

Although the activities performed and services provided by the electric sector are

essential to the whole population, which is an important ingredient to the development of

a country, the electrical systems can be categorized as critical systems where failure can result in significant financial loss, injury or threats to human life (Vitório, Masculo, & Melo, 2012) However, for those power plant in which the operators who have capability

of making decisions quickly and effectively can help the company to avoid fines and penalties by National Load Dispatch Center (Vitório et al., 2012) Hence, in order to survive and to create sustainable growth and development, companies are required to have a new approach to human resource management (Nguyen & Nguyen, 2012)

Pranee (2010) suggests that the most evident result of productivity improvement regarding QWL for sustainable development is in the industrial sector, where various improvements in applying technology and natural resources, as well as improvements in human resources, have taken place Furthermore, Bora, Das, and Murthy (2015) note that

by using QWL worker’s potential can be used to maximum extent And, Korunka,

Hoonakker, and Carayon (2008), Rego and Cunha (2008) are all agreed that "QWL is important for firms because it relates to employee performance productivity and loyalty” (as cited in Nguyen & Nguyen, 2012, p 88)

Quality of Work life

Kerce and Booth-Kewley (1993) argue that many authors have noted that workers are becoming better educated and that they now consider work as a tool for personal growth and social support rather than merely a means of achieving financial independence (as cited in Martel & Dupuis, 2006) In order to explain how important QWL is, Sirgy,

Efraty, Siegel, and Lee (2001, p 242) states that “there are some evidences showing that a happy employee is a productive employee; a happy employee is a dedicated and loyal employee; and QWL may have a significant impact on employee job performance”

Walton (1973) and Pereira and Labegalini (2002) stands out that QWL is used to assign innovative experiences carried through the attempt to rescue "ambient and

humanistic values neglected by the industrial societies in favor of the technological

advance, the industrial productivity and the economic growth"; and

attendance of the necessities and aspirations of the workers, including aspects related to a bigger participation of the employee in the decisions, orienting itself in direction to the industrial democracy, to the humanization of the work, emphasizing the social

responsibility of the companies

(as cited in Campos & Souza, 2006)

Although QWL may be viewed from different perspectives and has several

subcomponents, its various correlates that have been examined by different researchers and generally consist of “a multitude of job and organizational attitudes and behaviors” (Reilly, 2012, p 5) In the context of this study, the author use eight subscales of Walton (1973) to assess QWL, such as: Adequate and Fair Compensation, Safe and Healthy

Working Conditions, Immediate Opportunity to Use and Develop Human Capacities, Opportunity for Continued Growth and Security, Social Integration in the Work

Organization, Constitutionalism in the Work Organization, Work and Total Life Space, and Social Relevance of Work Life

Walton (1973) defines eight variables of QWL are as in Table 1:

Safe and Healthy

Working

Conditions

It is widely accepted in our society that workers should not be exposed to physical conditions or hourly arrangements that are unduly hazardous or detrimental to their health Legislation, union action, and employer concern have resulted in

continually rising standards of satisfactory working conditions

a few weeks or a few years, after which the blue-collar worker has reached nearly the peak of his earnings and can look forward to only minor improvements

Social Relevance

of Work Life

The socially beneficial roles of employing and the socially injurious effects of its activities have increasingly become salient issues for employees Organizations which are seen to be acting in a socially irresponsible manner will cause increasing numbers of employees to depreciate the value of their work and careers, which in turn affects worker self-esteem

Table 1 Definitions of QWL components

Regarding to performance measurement, DeNisi and Sonesh (2011), Levy and Williams (2004), Murphy and Dechert (2013), and Woehr and Roch (2012) agree that performance ratings by supervisors, peers, subordinates, or by oneself are ubiquitous (as cited in Campbell & Wiernik, 2015) After reviewing literature on job performance in last

15 years up to the point, Harari and Viswesvaran (2017, p 59) argue that “several content models of job performance have been postulated but despite the different terminology,

they are strikingly similar” and suggest that “a model of the job performance construct need not vary with the zeitgeist” Such a model is initially proposed by Viswesvaran (1993), and consists 10 job performance dimensions that comprehensively represents the entire job performance domain, such as: Overall job performance, Job performance or productivity, Quality, Leadership, Communication competence, Administrative

competence, Effort, Interpersonal competence, Job knowledge, and Compliance with or acceptance of authority

Viswesvaran, Ones, and Schmidt (1996) defines ten job performance dimensions

Quality Measure of how well the job was done Ratings of (or rankings of individuals on

statements referring to) the quality of tasks completed, lack of errors, accuracy to specifications, thoroughness, and amount of wastage

Leadership Measure of the ability to inspire, to bring out extra performance in others, to

motivate others to scale great heights, and professional stature; includes performance appraisal statements such as "gets subordinates to work efficiently,"

"stimulates subordinates effectively," and "maintains authority easily and comfortably."

Communication

competence

Skill in gathering and transmitting information (both in oral and written format) The proficiency to express, either in written or oral format, information views, opinions, and positions This refers to the ability to make oneself understood; includes performance appraisal statements such as "very good in making reports,"

"reports are clear," "reports are unambiguous," and "reports need no further clarification."

Administrative

competence

Proficiency in handling the coordination of different roles in an organization This refers to proficiency in organizing and scheduling work periods, administrative maintenance of records (note, however, that clarity is under Communication competence above), ability to place and assign subordinates, and knowledge of the job duties and responsibilities of others

Effort Amount of work an individual expends in striving to do a good job Measure of

initiative, attention to duty, alertness, resourcefulness, enthusiasm about work,

industriousness, earnestness at work, persistence in seeking goals, dedication, personal involvement in the job, and effort and energy expended on the job characterize this dimension of job performance

Interpersonal

competence

Ability to work well with others Ratings or rankings of individuals on cooperation with others, customer relations, working with co-workers, and acceptance by others, as well as nominations for "easy to get along with," are included in this dimension

Job knowledge Measure of the knowledge required to get the job done Includes ratings or

rankings of individuals on job knowledge, keeping up-to-date, as well as nominations of who knows the job best and nominations of who keeps up-to-date Compliance with

or acceptance of

authority

A generally positive perspective about rules and regulations; includes obeying rules, conforming to regulations in the work place, having a positive attitude toward supervision, conforming to organizational norms and culture, without incessant complaining about organizational policies and following instructions

Table 2 Definitions of job performance components

In electrical power plants, there are sets of processes, instruments and equipment designed for the transmission, generation, distribution, and commercialization of electric power Power plant operators typically perform the following: control power-generating equipment which may use any one type of fuel, such as coal, nuclear fuel, or natural gas; read charts, meters, and gauges to monitor voltage and electricity flows; check equipment and indicators to detect evidence of operating problems; adjust controls to regulate the flow of power; start or stop generators, turbines, and other equipment as necessary Their activities are characterized by significant mental and psychosocial demands, such as the time pressure, responsibility, amount of work, problem solving, decision-making, the high level of concentration required and adjustment to new technologies and have to carry it out by mobilizing knowledge and reasoning to which they have adequate training under the terms of the existing rules Based on definitions of job performance dimensions: Quality to measure of how well the job was done, Interpersonal competence to measure of ability to work well with others, Job knowledge to measure of the knowledge required to

get the job done, and Compliance with or acceptance of authority is a generally positive perspective about rules and regulations, the author use quality, interpersonal competence, job knowledge, and compliance with or acceptance of authority to assess individual job performance

Research model and Hypotheses

The research model is proposed as Figure 1

Figure 1 Research model

QWL and JP-Quality Compensation is a strategic component that is used to motivate

employee to achieve high performance (Larkin, Pierce & Gino, 2012) Promotions put employees to jobs that are more suitable for their abilities and skills (Gibbons, 1997) And

if employees’ work-family life is balance, the happy employees might have higher

performance Hence, employees work harder if they value monetary rewards and believe

that those awards result from their increased efforts and the desire of being promoted encourages the good employees to exert extra efforts to achieve performance goals With that in mind, this study hypothesized that

H1 QWL positively affects the Quality

QWL and JP-Job knowledge The company is providing training facilities for their

employees to develop their special abilities for the particular job which help them to gain knowledge and develop abilities and opportunity to develop abilities are considered to be the job factors that motivates employees performance to attain the target (Chandrasekar, 2011) With that in mind, this study hypothesized that

H2 QWL positively affects the Job knowledge

QWL and JP-Interpersonel competence Working in a harmony environment where

employees are friendly and ready to help and interact with each other, and where

employers are supportive and treat everyone equally, can result in improved employee performance as well as the performance of the whole organization Haynes (2007) finds the behavioral components of the office environment have the greatest impact on office productivity With that in mind, this study hypothesized that

H3 QWL positively affects Interpersonel competence

QWL and JP-Compliance with or acceptance of authority Kahn (1990) defined

psychological safety as the employee's "sense of being able to show and employ one's self without fear of negative consequences to self-image, status, or career" (p 708)

Dimensions of climate that are likely to be indicative of psychological safety include the extent to which: (1) management is perceived as flexible and supportive and employees

feel they have control over their work and the methods they use to accomplish it, (2) organizational roles and norms are perceived as clear, and (3) employees feel free to express their true feelings and core aspects of their self-concepts in their work roles When employees perceive that the organization accommodates their psychological needs

in the workplace, they are likely to respond by investing time and energy in the work of the organization (Brown & Leigh, 1996) With that in mind, this study hypothesized that

H4 QWL positively affects Compliance with or acceptance of authority

Methodology

Procedure and sample

The research was conducted at 4 combined cycle power plants (gas, DO fuel) with 2,700

MW capacity in the South of Vietnam where 21 thermal power plants (gas, DO, coal fuel) locate in with 14,208 MW capacity It consisted of two phases: preliminary research and main research The preliminary research was conducted by a qualitative study which was firstly in-depth interviewing with five expert who have at least five years’ experience in

power plant to check the clarity of the questionnaire (see Appendix 1 for the List of expert and their comments) and secondly was pilot test with 20 respondents (see Appendix 2 for

The pilot test result), to make appropriate adjustments where it was necessary and to ensure the Vietnamese questionnaire version be understood by most respondents; that contributed to the improvement of the official version

In the main quantitative one, the modified questionnaires were used for the survey

to collect data aimed at testing the measurement model and structural model Relating to sample, the nonprobability sampling technique - convenience sampling approach was

conducted and data was collected through paper survey of 204 operators Research

process included the following steps as illustrated in Figure 2

Figure 2 Research process

Measurement

A paper questionnaire was developed to collect data to validate the constructs and theory pointed in the research framework This questionnaire was firstly developed in English

(see Appendix 3), and was translated into Vietnamese (see Appendix 4) later Based on the

result of preliminary study, the instruction in Thọ (2011) and the supervisor’s guideline, the questionnaire was finalized in three parts (1) screening, (2) main, and (3) biodata with the result in which the number of item was modified (deleting 1 item of “Opportunity for Continued Growth and Security”, adding 1 item for “Job knowledge”), the items were re-arranged to shorten the questions, and different five-point measurement Likert scales were

applied to independent and dependent variables to reduce the bias (see Appendix 5)

For QWL, 35 measuring items were borrowed from Walton (1973), which were

used in da Silva Timossi, Pedroso, de Francisco, and Pilatti (2008) (see Table 3) The

WLSEC18 item was deleted due to the misunderstanding in the meaning The five-point Likert scale was used (1 = “very dissatisfy”, 2 = “dissatisfy”, 3 = “neither dissatisfy nor satisfy”, 4 = “satisfy”, 5 = “very satisfy”)

Components Coding Statements

Adequate and fair

compensation

WLCOM01 WLCOM02 WLCOM03 WLCOM04

o How satisfied are you with your salary (remuneration)?

o How satisfied are you with your salary, if you compare it to your colleagues' salary?

o How satisfied are you with the recompenses and the participation in results that you receive from the company?

o How satisfied are you with the extra benefits (alimentation, transport, doctor, dentist, etc.) that your company offers to you?

Safe and Healthy

Working

Conditions

WLHSE05 WLHSE06 WLHSE07 WLHSE08 WLHSE09 WLHSE10

o How satisfied are you with your weekly work journey (quantity of worked hours)?

o According to your workload (quantity of work), how do you feel?

o According to the use of technology in your tasks, how do you feel?

o How satisfied are you with the salubrity level (work conditions) in your workplace?

o How satisfied are you with the security equipment, individual and collective protection provided by your company?

o Regarding tiredness that your work cause to you, how do you feel? Immediate

Opportunity to

Use and Develop

Human Capacities

WLHUM11 WLHUM12 WLHUM13 WLHUM14 WLHUM15

o Are you satisfied with the autonomy (opportunity to make decisions) that you have at your work?

o Are you satisfied with the importance of the task/work/activity that you do?

o Regarding the polyvalence (possibility to performance several tasks and works) at work, how do you feel?

o How satisfied are you with your performance evaluation (awareness

of how good or bad have been your performance at work)?

o Regarding possibilities conferred (work responsibility given to you), how do you feel?

o How satisfied are you with your opportunity of professional growth?

o How satisfied are you with the trainings you participate?

o Regarding the situations and the frequency that occur the resigning at your work, how do you feel?

o Regarding the incentive that your company gives you to study, how

o Regarding the discrimination (social, racial, religious, sexual, etc.) in you work, how do you feel?

o Regarding your relationship with your colleagues and bosses at work, how do you feel?

o Regarding your team's and colleagues' commitment to work, how do you feel?

WLSIO22 o How satisfied are you with the valorization of your ideas and

o How satisfied are you with the company for respecting the workers' rights?

o How satisfied are you with your freedom of expression (opportunity

to give opinions) at work?

o How satisfied are you with the norms and rules at your work?

o Regarding the respect to your individuality (individual characteristics and particularities) at work, how do you feel?

Work and Total

Life Space

WLBAL27 WLBAL28 WLBAL29

o How satisfied are you with the work influence on your family life/routine?

o How satisfied are you with the work influence on your possibilities

o Regarding the proud of performing your work, how do you feel?

o Are you satisfied with the image this company have to society?

o How satisfied are you with the communitarian integration (contribution to the society) that the company have?

o How satisfied are you with the services and the quality of products that the company makes?

o How satisfied are you with the human resources politic (the way that the company treats the workers) that the company has?

Table 3 QWL measurement items

For JP, in this study, based on the definitions of components given by

Viswesvaran, Ones, and Schmidt (1996) and the research context, 16 items were used to measure Quality, Interpersonal competence, Job knowledge, and Compliance with or

acceptance of authority (see Table 4) in order to assess job performance A JPKNL45

item was added to fit the research context The five-point Likert scale was used (1 =

“strongly disagree”, 2 = “disagree”, 3 = “neither disagree nor agree”, 4 = “agree”, 5 =

“strongly agree”)

Components Coding Statements

Quality JPQUA35

JPQUA36 JPQUA37 JPQUA38 JPQUA39

o My job has been done well

o My job has been done with lacks of errors

o My job has been done accuracy to specifications

o My job has been done with thoroughness

o My job has been done with lacks of accidents

Interpersonal

competence

JPINT40 JPINT41 JPINT42

o I have ability to work well with supervisor

o I have ability to work well with crew’s members

o I have ability to work well with co-worker

Job knowledge JPKNL43

JPKNL44 JPKNL45

o My job has been done with job knowledge

o My job has been done with up-to-date knowledge

o With my job knowledge, I can carry out the other crew’s member position

Compliance with

or acceptance of

authority

JPAUT46 JPAUT47 JPAUT48 JPAUT49 JPAUT50 JPAUT51

o I generally have positive perspective about rules and regulations, such as obeying the rules

o I generally have positive perspective about rules and regulations, such as conforming to regulations

o I generally have positive perspective about rules and regulations, such as having positive attitude toward supervision

o I generally have positive perspective about rules and regulations, such as conforming to organizational norms and culture

o I generally have positive perspective about rules and regulations, such as without incessant complaining about organization policies

o I generally have positive perspective about rules and regulations, such as following instructions

Table 4 Job performance measurement items

The methods of data analysis included testing Cronbach’s alpha using IBM SPSS software, testing Confirmatory Factor Analysis (CFA) and Structural Equation Modeling (SEM) using IBM AMOS software CFA is data analyzing technique aiming to supply confirmatory test of research measurement theory And SEM is a set of statistical model that combines multivariate technique and multiple regressions in order to simultaneously investigate the wide range of interrelated relationship which was in hypothesized model, including the relation between variables and factors or between latent constructs (Hair et al., 2009)

Data analysis, Results, and Discussion

After data collection, total 204 responses were collected However, only 198 responses were qualified for data analysis process 6 questionnaires were eliminated because they were invalid (respondents just chose one option for all questions; missed to answer some

questions) Finally, 198 questionnaires were used as valid data for this research

Scale reliability and validity

Firstly, Cronbach's alpha was used to test the internal consistency for each measurement component separately in SPSS The resulting Cronbach’s alpha values of all

measurement component ranged from 73 to 91, which was acceptable as higher than 7 (Pallant, 2005)

Then, CFA were used for all of constructs in research model, see Figure 3

Figure 3 The Measurement Model combining All Latent Constructs Simultaneously

Unidimensionality is achieved when the measuring items have acceptable factor loadings (≥ 6) (Nunnally, 1978) Items WLHSE7, WLHSE8, WLHSE9, WLSIO19 were deleted due to its factor loading < 6

Discriminant validity is achieved when the measurement model is free from

redundant items In case AMOS identify the pair of redundant items in the model in term

of high Modification Indices, one of the items should be deleted or the correlated pair should be set as “free parameter estimate” (Awang, 2012) Items WLHUM11, WLSRL32, WLSRL34, and JPAUT47 were deleted and pair items WLCON23, WLCON26 was set as

“free parameter estimate” due to its high Modification Indices

Awang (2012) states that the output of Standardized Residual Covariance could be examined as a guideline to the “wellness” of the structural model The residual

covariance is the difference between the sample covariance and the model-implied

covariance The model is correctly specified if most of the standardized residuals are less than two in absolute value Items WLCOM03, WLHUM12, WLSEC17, WLCON25, WLSRL33, JPQUA36, JPKNL45, and JPAUT50 were deleted due to its high

standardized residuals

Composite Reliability with a value > 6 is required in order to achieve composite reliability for a construct The average percentage of variation as explained (AVE) by the measuring items for a construct > 5 is required Based on the result shown in Table 5, components HSE, SEC, SIO were deleted due to its low AVE

Adequate and fair compensation COM 0.564 0.794

Safe and Healthy Working Conditions HSE 0.446 0.707

Immediate Opportunity to Use and Develop Human Capacities HUM 0.516 0.761

Opportunity for Continued Growth and Security SEC 0.473 0.642

Social Integration in the Work Organization SIO 0.447 0.708

Constitutionalism in the Work Organization CON 0.596 0.815

Social Relevance of Work Life SRL 0.680 0.809

Compliance with or acceptance of authority AUT 0.605 0.860

Table 5 Average Variance Extracted and Composite Reliability

Construct validity is achieved when the Fitness Indexes for a construct achieved the required level The fitness indexes and the level of requirement are as follow: Root Mean Square of Error Approximation (RMSEA) < 0.08 (Browne & Cudeck, 1993), Goodness of Fit Index (GFI) > 0.90 (Joreskog & Sorbom, 1984), Comparative Fit Index (CFI) > 0.90 (Bentler, 1990), Tucker-Lewis Index (TLI) > 0.90 (Bentler & Bonett, 1980), Chi Square/Degrees of Freedom (Chisquare/df) < 5.0 (Marsh & Hocevar, 1985) (as cited

in Awang, 2012) The final measurement model had a good fit to the data: Chi-square = 395.092; df = 287; Chisquare/df = 1.377; P = 000; GFI = 878; CFI = 965; RMSEA = 044 The next step was to model this constructs into structural model for analysis using SEM

Structural Equation Modeling (SEM)

The purpose of applying SEM was to test whether the hypotheses proposed in the

literature review existed or not The SEM results in the Figure 3 showed that the

theoretical model received an acceptable fit to the data: Chi-square/df = 1.487, GFI = 861, TLI = 945, CFI = 952, RMSEA = 050 Based on the result, all measurements index were good excepted GFI index with dissatisfied value

Figure 4 The Standardized Regression Weights for the SEM

As shown in Figure 4, the standardized beta estimate for effect of QWL on QUA is

.51, while the standardized beta estimate for INT is 59, for KNL is 43, and for AUT is 51 The value of coefficient of determination R2 is 26 for QUA, is 35 for INT, is 18 for KNL, and is 27 for AUT It indicates that the contribution of exogenous constructs QWL

in estimating the endogenous construct QUA is 26%, INT is 35%, KNL is 18%, and AUT

is 27% The result in Table 6 shown that all of the regression weight values were positive and significant (p < 001), and it supported all four hypotheses

β S.E C.R P value H1 QWL  JP-QUA 628 125 5.025 000 Supported

H2 QWL  JP-INT 835 154 5.423 000 Supported

H3 QWL  JP-KNL 594 129 4.596 000 Supported

H4 QWL  JP-AUT 748 141 5.305 000 Supported

Table 6 The Regression Weights for QWL in predicting QUA, INT, KNL, and AUT

Discussion

In the context of electrical power plant, number of operator is about one third of total number of employees in the organization While the operators have irregular

schedule, the rest employees have regular schedule It might lead to the poor social

connection between operators and the others Even in operational community itself, an operator uses to communicate with screw member This could be the reason that Social Integration in the Work Organization component of QWL was eliminated from this

research

As mentioned before, this research was carried in 4 combined cycle power plants

In term of efficiency, safety and environment operation, combined cycle power plant is better than the power plants with other technology (Langston, 2013) Hence, the sample chosen in this research might not well represent the population of this research context It would effects the reliability of the survey’s result It would also lead to the high

correlation between JP components whose residuals were set double head arrow in

between in order to achieve Model Fit indices in SEM excepted the GFI index

Furthermore, this survey was conducting during the working time of the operators, which would also effect the survey’s result because of the non-respond bias

A power plant is a component of national electrical grid In term of safety working environment, a power plant has to strictly follow national regulation and standard (The National Assembly, 2001, 2015) This could be the reason that Safe and Healthy Working