Performance refers to the degree to which an employee achieves the expected quality and quantity of work in line with their assigned responsibilities. It reflects the individual’s ability to deliver measurable results in completing tasks set by the organization. Bintoro and Daryanto (2017) define performance as an indicator of whether organizational goals have been achieved, noting that managers often give attention to it only when problems become significant.

Job satisfaction can be described as an employee’s emotional response toward their work, encompassing feelings of support or dissatisfaction related to job conditions, work situations, relationships with colleagues, and the work environment. It reflects attitudes shaped by cooperation, rewards, and both physical and psychological factors, as well as the overall experiences encountered in the workplace (Mangkunegara, 2017; Agustini, 2019; Afandi, 2018; Handoko, 2020).

Work discipline refers to efforts aimed at fostering employee awareness and willingness to comply with company regulations. It serves as both a managerial tool to guide behavioral change and a form of training designed to improve knowledge, attitudes, and cooperation, ultimately enhancing employee performance (Hendrayani, 2020; Zahara & Hidayat, 2017).

The work environment encompasses all conditions surrounding employees that can influence their performance, including lighting, noise levels, temperature, humidity, ventilation, cleanliness, safety, and the adequacy of work equipment (Sukanto & Indroyo, 2018; Afandi, 2018).

Motivation can be seen as the driving energy that encourages a person to utilize their abilities, skills, and knowledge in order to reach optimal results. It not only initiates action but also directs and sustains it toward specific objectives—such as improving productivity, maintaining commitment, and ensuring consistent attendance. In the workplace context, motivation shapes how employees approach their tasks and influences their overall performance (Umpung, 2020; Kurnia & Nugroho, 2019).

This study adopts a quantitative approach with a causal research design, aiming to examine the cause-and-effect relationship between independent and dependent variables (Sugiyono, 2022). Data were collected through surveys by distributing questionnaires to the selected respondents. The population consisted of 248 non-managerial permanent employees at PDAM Tirtanadi Medan City. Using a simple random sampling technique, each member of the population had an equal chance of being selected, based on middle-to-low job level criteria. Applying the Slovin formula, the final sample comprised 154 non-managerial employees.

The path coefficient analysis shows that work discipline has a positive and significant impact on job satisfaction at PERUMDA Tirtanadi Medan. A mean score of 4.37 indicates that discipline is generally good but still requires improvement, with the lowest score (4.31) on the statement “Always follow directions from superiors.” These findings align with previous studies (Pridana & Setia, 2017; Hafidzh & Hartono, 2022; Dirman & Setyaningrum, 2023; Windi & Lahamid, 2024; Suryandini, 2021), which confirm that better work discipline is associated with higher job satisfaction.

The path coefficient analysis confirms that work discipline has a positive and significant impact on job satisfaction at PERUMDA Tirtanadi Medan. Discipline fosters an orderly work environment, boosts productivity, and minimizes stress and conflict, while reflecting both personal responsibility and adherence to organizational rules.

Survey results from 154 respondents show a mean score of 4.37 for work discipline, indicating room for improvement. The lowest mean score, 4.31, was recorded for the statement “Always follow directions from superiors,” suggesting that some employees still demonstrate lower discipline levels. These findings are consistent with prior studies (Pridana & Setia, 2017; Hafidzh & Hartono, 2022; Dirman & Setyaningrum, 2023; Windi & Lahamid, 2024; Suryandini, 2021), which conclude that greater work discipline leads to higher job satisfaction.

The path coefficient results indicate that work discipline has a positive and significant effect on job satisfaction at PERUMDA Tirtanadi Medan. Discipline supports an orderly work environment, enhances productivity, and reduces stress, reflecting both personal responsibility and adherence to organizational rules.

From the survey of 154 respondents, the work discipline variable recorded a mean score of 4.37, showing the need for improvement. The lowest score, 4.31, was for the statement “Always follow directions from superiors,” indicating that some employees still display low discipline. These results align with previous studies (Pridana & Setia, 2017; Hafidzh & Hartono, 2022; Dirman & Setyaningrum, 2023; Windi & Lahamid, 2024; Suryandini, 2021) which found that higher work discipline leads to greater job satisfaction.

The path coefficient analysis shows that work discipline has a positive and significant impact on employee performance at PERUMDA Tirtanadi Medan. Strong discipline enables employees to work systematically, meet deadlines, and achieve targets, thereby improving productivity and work quality. Conversely, low discipline can cause delays and reduce efficiency, making it essential for organizations to enforce clear rules, maintain consistent supervision, and apply balanced sanctions and rewards.

From 154 respondents, the work discipline variable had a mean score of 4.37, categorized as high but still requiring improvement. The lowest score, 4.31, was for the statement “Always follow directions from superiors.” These results are consistent with previous studies (Hafizh & Hartono, 2022; Hafizah, 2023; Putri et al., 2022), which found that higher work discipline leads to improved employee performance.

Based on the statistical testing results of the path coefficients test, it shows that the work environment has a positive and significant effect on employee performance. The work environment is very important in influencing employee performance because it can build a sense of security and comfort from within.

The work environment is an important factor that directly affects the level of employee performance. A conducive work environment both physically and psychologically can increase the comfort, concentration, and enthusiasm of employees in carrying out their duties. Factors such as adequate lighting, cleanliness of the workspace, comfortable room temperature, and adequate supporting facilities contribute to work efficiency.

The results of this study are in line with research conducted by Andri and Kuswati (2024); Zahro et al (2024); Hurriyah (2024) which states that the work environment affects employee performance, which means that the more ideal the work environment, the higher employee performance. Conversely, the worse the work environment of an employee, the lower his performance. However, the results of this study are not in line with research conducted by Kitta et al (2023); Miuna and Isnowati (2022) state that work discipline has no effect on performance.

The path coefficient analysis confirms that work motivation has a positive and significant influence on employee performance at PERUMDA Tirtanadi Medan. High motivation encourages employees to be more active, confident, and proactive, thereby improving productivity and work quality. Conversely, low motivation can reduce morale, increase errors, and raise turnover risk.

From 154 respondents, the mean score for work motivation was 4.10, with the lowest score found in the statement “Motivated to work because I need a work policy” (mean = 3.53), indicating areas for improvement. These findings are consistent with Seran et al. (2023), Rifai et al. (2021), and Richard et al. (2022), who assert that higher motivation correlates with better performance, but differ from Saputra et al. (2023), who found no such relationship.

The path coefficient analysis indicates that job satisfaction has a positive and significant effect on employee performance. High job satisfaction can enhance motivation, loyalty, and commitment, while dissatisfaction may reduce performance.

From 154 respondents, the mean score for job satisfaction was 4.29, indicating a generally high level but with room for improvement. The lowest score appeared in the statement “Satisfied with the promotion” (mean = 4.29), suggesting that some employees still experience low satisfaction. These findings align with Andri and Kuswati (2024), Zahro et al. (2024), and Putri et al. (2022), who confirm that higher job satisfaction is associated with improved performance.

Statistical testing results indicate that work discipline positively and significantly influences employee performance through the mediating role of job satisfaction. This finding suggests that improved work discipline can indirectly enhance performance at PERUMDA PDAM Tirtanadi by increasing employee job satisfaction.

The results of statistical testing on the indirect effect show that the work environment has a positive and significant impact on employee performance through the mediation of job satisfaction. This implies that improvements in the work environment can indirectly enhance performance at PERUMDA PDAM Tirtanadi by increasing employee job satisfaction.

The results of statistical testing on the indirect effect indicate that work motivation has a positive and significant impact on employee performance through the mediation of job satisfaction. This finding suggests that higher work motivation can indirectly enhance employee performance at PERUMDA PDAM Tirtanadi by increasing job satisfaction.