Comprehensive Analysis of Physical and Mental Workloads for Electronic Installation Workers Utilizing CVL and NASA-TLX at the Building X Construction

This research was conducted directly using objective and subjective measurement methods. Objective research will be carried out using a physiological approach to employees that can be quantified by changes in the function of the employee's body. In contrast, subjective research is carried out based on the perception/subjectivity of the employee. In addition, this study's first data collection method was observation, which measured the pulse rate using the Pulse Oximeter type LED AB-98 (Mixio, Indonesia) directly when employees carried out work and when resting. This pulse measurement is carried out to determine the physical workload of employees. The pulse measurement method or CVL method refers to research [17] where pulse data will be carried out two times at the time before work at 08.00–09.00 and at work time 09.00-11.30, and the measurement is carried out for seven days.

The second method of data collection is to conduct interviews and disseminate NASA-TLX questionnaires, where employees will be asked to determine rating values against six subscales on NASA-TLX consisting of Mental Demand (MD), Physical Demand (PD), Temporal Demand (TD), Performance (PF), Frustration Level (FR), and Effort (EF).

2.1 CVL method

CVL is a method used to measure a person's physical workload by monitoring their pulse rate [18]. This method involves identifying respondents based on age, gender, length of service, type of work, and hours of work and rest. The employee's pulse is measured by clamping the Oximeter tool to their fingers. Pulse measurement is carried out twice: first, when the employee is not working, and second, when the employee is performing their work. Based on the outcomes of the two pulse measurements, we can calculate the percentage of CVL by applying Eq. (1). This equation allows us to quantify the variability or concentration of the measured parameters, providing valuable insights into the data collected from the measurements [19].

$\% C V L=\frac{100 x(working\,pulse-resting\,pulse)}{(max. working\,pulse-resting\, pulse)}$             (1)

Information:

1. The maximum pulse rate for men is 220-age.

2. The maximum pulse rate for women is 200-age.

The maximum working pulse for men can be calculated using the formula (220-age), while for women it is (200-age). Once the results have been calculated using the CVL percentage equation, the physical workload can be studied based on the classification standards listed in Table 1 [20].

Table 1. CVL classification standards

2.2 National aeronautics and space administration-task load index (NASA-TLX)

The NASA-TLX method, developed by the National Aeronautics and Space Administration, measures an individual's mental workload. This method involves distributing questionnaires to respondents, who then provide subjective ratings on six different subscales using a scale of 0 to 100. The NASA-TLX method, on the other hand, involves conducting interviews and disseminating questionnaires to employees, where they will be asked to determine rating values against six subscales on NASA-TLX consisting of as follows: (1) Mental Demand (MD) refers to the cognitive effort required for task completion, including perception, decision-making, and memory load; (2) Physical Demand (PD) refers to the physical activity, strength, and endurance required to perform a task, encompassing factors such as manual handling, repetitive motions, and overall bodily exertion; (3) Temporal Demand (TD) refers to the stress associated with performing tasks under time constraints or pressure; (4) Performance (PF) refers to how effectively and efficiently tasks are executed, encompassing output quality, accuracy, and speed of completion; (5) Frustration Level (FR) refers to the degree of annoyance or dissatisfaction experienced by individuals when facing obstacles or challenges during task performance. It is associated with the emotional response to difficulties encountered during task execution; (6) Effort (EF) involves the physical and mental exertion invested in task performance, including energy, concentration, and determination [21].

Six subscales of the NASA-TLX are necessary to evaluate the workload of workers involved in electronic installations through a comprehensive mental analysis that encompasses various types of work, including (1) installation of telecommunications systems, (2) testing of horn strobe/fire alarms, and (3) testing of telecommunications systems. Work in the field of electronic installations requires both mental and physical efforts, as it demands high levels of concentration and the capacity to achieve specific objectives while delivering results that meet or exceed expectations. When organizational targets are set high and employees are unable to complete their tasks within the designated working hours, they may find themselves compelled to work overtime, ultimately affecting their ability to meet these targets [22].

Table 2. Subscales comparing NASA-TLX factors

Table 3. Mental Workload Interpretation of NASA-TLX Methods

According to Hart and Staveland [18], the NASA-TLX method for measuring mental workload involves the following steps: (a) explain the six NASA-TLX measurement subscales to respondents to determine rating values; (b) compare and assign weights to 15 paired subscales as shown in Table 2 [18].

a. Calculate the value of the product by multiplying the predetermined rating value by the weighting result using Eq. (2) as follows [17]:

$Product= rating\, x \, weight \, factor $                 (2)

b. Calculate the workload value (weighted workload) using Eq. (3) as follows [17]:

$W W L=\Sigma \, product$            (3)

c. Calculate the average score to determine the category of mental workload experienced by employees using Eq. (4) as follows [17]:

$ Average\, score =\frac{W W L}{15}$                (4)

d. Determine the category of mental workload and determine the interpretation of the workload experienced by respondents based on the mental workload intervals of the NASA-TLX method, which can be seen in Table 3 [18].

Based on the results of measuring physical and mental workloads, the top three factors causing mental workload are the work environment (temperature, lighting, vibration, and noise), fatigue/saturation, and air and dust pollution. To reduce the workload experienced by employees of electronic installations, improvement efforts can be proposed by referring to the Hierarchy of Risk Control in Occupational Safety and Health based on ISO 45001:

4.1 Engineering controls

To address and reduce the issue of an unsafe work environment and activities that may pose a danger, design, and engineering controls can be implemented by providing a proper lighting environment. Certain working areas need more lighting sources or have no lighting at all. The absence of adequate lighting in these areas can lead to eye strain and fatigue, as employees are forced to work in low-light conditions. By examining the various factors that impact work performance, valuable insight can be obtained to optimize lighting design and operation for better overall performance. The research conducted by Konstantzos et al. [36] found that task performance improves with brighter lighting, contrast ratios between 7:1 and 11:1 (while ensuring glare is avoided), and higher correlated color temperatures. Moreover, adjusting the lighting spectrum towards red or blue wavelengths has also demonstrated beneficial effects [36].

4.2 Administrative controls

The division of duties can be adjusted as part of our administrative controls to reduce the workload on employees. By reorganizing the allocation of tasks, the high mental load experienced by employees can be addressed. This may be due to imbalanced task distribution and differing employee abilities, leading to fatigue and decreased productivity. To ensure effective and efficient distribution of employee duties, clearly defining job specifications in written form is essential. This includes outlining the required employee qualities, educational qualifications, physical, technical, emotional, and communication skills, and work experience needed to carry out the responsibilities associated with a particular job effectively.

Ensuring job satisfaction is essential for driving employee productivity and reducing organizational turnover. Inegbedion et al. [37] proposed a model outlining the significant factors influencing job satisfaction. They emphasized that employees' satisfaction with their jobs is heavily impacted by how they perceive the balance of their workload. They focused on three key factors: comparing their workload to that of their coworkers, the organization's staffing levels, and how well their roles align with their responsibilities [37].

4.3 Personal protective equipment

One way to improve working conditions for electronic installation employees is by providing appropriate personal protective equipment (PPE). The work environment, including temperature, lighting, noise, vibration, and dust pollution, can contribute to mental workloads. Personal protective equipment, such as earplugs and masks, can help address these challenges. Earplugs can protect employees from excessive noise in the project area, while disposable paper, cotton, or gauze masks can shield employees from dust, ensuring better breathing conditions [38].