Ergonomics, Vol. 48, No. 15, 15 December 2005, 1721 – 1733
Characteristics of job rotation in the Midwest US manufacturing sector MICHAEL JORGENSENy*, KERMIT DAVISz, SUSAN KOTOWSKIz, PRANATHI AEDLAy and KARI DUNNINGx yIndustrial and Manufacturing Engineering Department, Wichita State University, Wichita, KS, USA zDepartment of Environmental Health, University of Cincinnati, Cincinnati, OH, USA xCollege of Allied Health Sciences, University of Cincinnati, Cincinnati, OH, USA
Job rotation has been advocated as a suitable intervention to control workrelated musculoskeletal disorders. However, little is known regarding the prevalence of job rotation, methods used to identify jobs for rotation or the benefits or limitations of job rotation. A web-based questionnaire was developed to survey job rotation practices from Midwest US manufacturing companies. Results indicated that 42.7% of the companies contacted used job rotation, where the median time for which they had used job rotation was 5 years. Job rotation was used mainly to reduce exposure to risk factors for work-related injuries and to reduce work related injuries, whereas supervisor decisions and ergonomic analyses were used to select jobs for the rotation scheme. Major limitations to successful implementation of job rotation included rotation of individuals with medical restrictions, decreased product quality and lack of jobs to rotate to. These findings suggest that further study is needed to determine if exposure to risk factors is reduced through current efforts. Keywords: Job rotation; Intervention; Musculoskeletal disorders; Risk factors; Administrative controls
1. Introduction With tremendous profit demands for companies in the current economy, there is a need to develop alternatives to potentially costly equipment and re-designs of the work area when attempting to prevent work-related musculoskeletal disorders (WMSDs). One intervention strategy may be job rotation due to the potential relatively low implementation costs. The premise of job rotation is that workers rotate from job to job in a given time period, with the objective of minimizing the accumulated biomechanical loading on a particular body part for all workers. The effectiveness of the job rotation depends in part upon how
*Corresponding author. E-mail:
[email protected] Ergonomics ISSN 0014-0139 print/ISSN 1366-5847 online ª 2005 Taylor & Francis http://www.tandf.co.uk/journals DOI: 10.1080/00140130500247545
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well the biomechanical stressors are balanced across body parts. If a worker rotates from a job that places excessive stress on the low back to another job that also places stress on the low back, the rotation scheme may be ineffective in controlling risk of injury to the low back (Frazer et al. 2003). Thus, an optimal job rotation scheme may minimize the stress on each of the body regions by ensuring that the jobs in the rotation scheme alternate the physical demands on different body parts. However, little is known about how job rotation is practised in the manufacturing sector. The practice of job rotation is not new, and in fact has been well researched in the personnel management literature as a method to motivate and increase skills of employees (Cheraskin and Campion 1996, Gittleman et al. 1998). Job rotation, typically defined as rotation from one job to another, has been claimed to have the following benefits: morale building; productivity improvement; improved worker retention; opportunity for training; and ability to enhance career development (Farrant 1987, Cheraskin and Campion 1996). Gittleman et al. (1998), in an analysis of alternative work organization practices in private non-agriculture establishments in the United States (e.g. worker teams, total quality management, quality circles, job rotation) from a 1993 Bureau of Labor Statistics survey found that 12.6% of the establishments surveyed had implemented job rotation, whereas 24.2% of the surveyed establishments with 50 or more employees had implemented job rotation. Job rotation was defined as: ‘a work design system that allows employees to rotate between different jobs’. However, it was not indicated as to whether this was rotation among jobs as an intervention strategy for prevention of WMSDs or for other purposes such as increasing morale, cross training, or career development. From a WMSD intervention perspective, very little about job rotation practices is known. This includes a lack of epidemiological investigation, assessment of the process for identifying the jobs to include in a job rotation scheme, as well as the effectiveness in addressing WMSD risk factors and resulting outcomes. In an assessment of the number of jobs in the industrial and service sectors across the United States that contain lifting and lowering to determine the proportion that are valid for analysis of the National Institute for Occupational Safety and Health (NIOSH) Lifting Equation (Waters et al. 1993), Dempsey (2002) found that 23% of the jobs involved job rotation. One epidemiological study found an odds ratio of 6.3 for the lack of job rotation and the occurrence of carpal tunnel syndrome (Roquelaure et al. 1997), whereas Wellman et al. (2004) found that 19% of Massachusetts manufacturing facilities used job rotation as an intervention method for individuals with work-related carpal tunnel syndrome. The use of job rotation as an intervention strategy has been suggested by federal agencies responsible for research and enforcement of safety and health. The Occupational Safety and Health Administration’s (OSHA) recently rescinded Ergonomics Program final rule allowed administrative controls (e.g. job rotation) to be used to reduce WMSD hazards (Federal Register 2000). NIOSH has published several health hazard evaluation reports on assessments of WMSDs, where job rotation has been suggested as a potential control strategy (National Institute for Occupational Safety and Health 1990, 1991, 1992, 1995, 1996). No guidance on how to develop job rotation schemes to reduce WMSD hazards was given by OSHA, whereas NIOSH suggested that jobs be identified to rotate to those that use different muscle and tendon groups. Several studies report on the practice and development of job rotation schemes within individual companies. Hazzard et al. (1992) reported on a television manufacturer’s experience in implementing a mandatory job rotation procedure and the obstacles they encountered, which included inappropriately rotating to jobs with similar risk factors,
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labour union grievances, and lack of job skill of some employees when rotating. Estill and MacDonald (2002) reported that a Midwest manufacturer of laundry equipment practised mandatory job rotation, with rotation of employees to another job performed on an hourly basis. Henderson (1992) developed rotation schemes for a poultry processing plant, where every job was rated on a scale ranging from low to high physical stress. The job rotation schemes were devised such that no back-to-back high stress positions were performed after each other (e.g. a low-stress job preceded and followed a high-stress job). Thus, the strategy when using job rotation for prevention of WMSDs is to reduce the exposure to WMSD risk factors such that the cumulative exposure throughout an individual’s work shift is reduced below soft tissue injury thresholds. However, very little guidance exists for practitioners to devise such schemes. Whilst job rotation has been recommended as a viable intervention practice by both OSHA and NIOSH, there are several voids in the research literature regarding this intervention strategy. First, little is known about the prevalence of job rotation as an intervention strategy for WMSDs in the manufacturing sector. Second, for the manufacturing establishments who do use job rotation, little is known about their objectives in the use of job rotation, as well as the perceived benefits and limitations encountered during the utilization of job rotation. Third, little is known regarding how jobs are identified in existing job rotation schemes in the manufacturing sector. Thus, with consideration of these identified voids in the literature, the objectives of this study were to assess the current utilization of job rotation from a sample of manufacturers in the Midwest United States, and to ascertain the level of perceived benefits and limitations associated with the implementation of job rotation.
2. Methods 2.1. Approach This study consisted of randomly contacting persons responsible for safety and health in manufacturing companies in the Midwest United States. These representatives were asked to complete a web-based questionnaire on the characteristics of job rotation practices within their facility. This study and protocol was approved by the Institutional Review Board for Human Subjects at each of the authors’ individual academic institutions. 2.2. Survey sample The survey sample consisted of manufacturing companies (standard industrial classification (SIC) codes between 20 and 39) in and around the Wichita, Kansas and Cincinnati, Ohio geographical areas. Potential companies were randomly selected from directories of manufacturers for the states of Kansas, Ohio, Kentucky and Indiana. Telephone contact was made with individuals responsible for safety and health or human resources (e.g. human resources manager, safety coordinator or safety engineer) within each of the manufacturing facilities. The objectives of the research and questionnaire were explained to the individual. If the contact agreed to complete the questionnaire, a follow-up email was sent to the individual, explaining the research objectives, as well as the web link address for the online job rotation questionnaire. If the contact did not have access to the Internet, a copy of the questionnaire was faxed to the contact. Follow-up phone contact was made after 1 month and 3 months after initial
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contact if the survey was not completed. For contacts who refused to complete the survey, a simple question was asked on the telephone about whether the company was currently or had previously utilized job rotation. 2.3. Job-rotation survey The job rotation survey consisted of questions regarding company demographics, such as company size (i.e. 1 – 10, 11 – 49, 50 – 249, 250 – 499, 500 – 1000 and 1000 þ employees), products manufactured, presence of a labour union (yes or no), job rotation practices (e.g. how long job rotation had been utilized, number of job rotation schemes, duration on jobs before rotating to the next job), and five separate categories with questions that were answered with 5-point Likert scale responses. Questions were constructed with an effort to minimize bias (Dillman 2000). The five question categories and specific question areas were: 1.
2.
3.
4.
5.
Objectives of initiating job rotation: increasing job satisfaction, employee skill, productivity and quality, and reducing mental stress, absenteeism and turnover, injury/illness incidence/severity rates; Factors considered when devising job rotation schemes: impact on production, proximity of jobs to rotate to, pay scales of different jobs, cycle times, employee skill level, medical restrictions of employees and exposure to risk factors for injuries/ illness; Methods used in developing job rotation schemes: schemes determined by employees or supervisors, ergonomic analyses, time studies and consideration of medical restrictions; Perceived benefits realized from implementing job rotation: increased skill of the employees, productivity, quality or employee morale or satisfaction or reduced absenteeism, injury/illness incidence/severity rate or lower turnover; Perceived limitations and obstacles experienced when implementing job rotation: union contracts, rotating to jobs with different pay scales, rotating employees with medical restrictions, lack of jobs to rotate to, lack of methods to identify jobs for rotation, lack of job diversity, decreased quality, decreased job satisfaction and increase in absenteeism or turnover.
2.4. Survey statistical analyses For each question, descriptive statistics were generated for the mean and median response from the 5-point Likert scales. Comparison of the mean magnitudes of the responses within each question category was performed by using the 95% CI using the t-statistic for small sample sizes. Additionally, correlation analysis was performed for each question as a function of company size, number of years utilizing job rotation and labour union status (i.e. yes or no) (Cohen and Cohen 1983). 2.5. Survey repeatability analysis The repeatability of the job rotation survey questions was tested with a test – retest procedure. Twenty-five company representatives who completed the online survey were contacted at least 2 weeks after completion of the original survey, where the average time of the second contact was approximately 3 weeks, and were asked to complete a second
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online survey (identical to the first). Each of the companies that completed the original survey was asked to complete an identical questionnaire, thus the repeatability population was a sample of convenience. The company representatives were provided with a token monetary reward for the repeated survey completion. Repeatability of the questionnaire data was assessed using the kappa statistic, absolute error, percentage with identical values and percentage with minimal error.
3. Results 3.1. Survey response rates A total of 233 companies were contacted (i.e. personal contact was made with an individual within the company). Of those 233 companies, 178 (76.4%) agreed to provide information regarding their job rotation status and 55 (23.6%) refused to provide any information at all. Of the 178 companies that provided their job rotation status, 102 companies did not use job rotation whereas 76 companies indicated they did use job rotation. This represents a job rotation prevalence of 42.7%. Of the 76 companies that indicated that they did use job rotation, 38 (50%) completed the job rotation questionnaire, and 38 companies did not complete the questionnaire. 3.2. Job rotation survey question responses For the 38 companies that indicated that they utilized job rotation and completed the survey, the median company size category was 50 to 249 employees and they ranged from the 11 – 49 to 1000 þ employee categories. The median number of years utilizing job rotation was 5.0 years (where 83% of the companies had been using job rotation for more than 2 years), and the median duration of time on a job before rotating to the next job was 2.0 h. Additionally, 25% of the companies that utilized job rotation reported that labour unions were present in their facility. The descriptive and statistical comparisons of the response ratings under the five survey question categories are shown in table 1. The major ‘objective’ for initiating job rotation was reportedly to reduce the incidence and cost of work-related injuries. The second most important ‘objective’ was reportedly to increase employee skill. Addressing issues related to production, mental stress, quality and job satisfaction were rated as the third most important ‘objective’. When asked about what ‘factors’ were considered when devising the job rotation schemes, reduction of risk factor exposure generated the highest rating of importance, followed by the impact job rotation would have on production. Consideration of jobs that employees with medical restriction typically work on was considered the least important. The ‘method’ used to develop rotation schemes was primarily driven by supervisor decisions, followed by ergonomic job analyses; however, these were not statistically different. Considering direct input from employees was the next highest rated ‘method’ used to develop job rotation schemes. Among the perceived ‘benefits’ from utilizing job rotation, respondents indicated that an increase in the skill of the employees was the highest benefit, followed by a decrease in incidence/symptoms of work-related injuries and an increase in employee morale or satisfaction. Finally, rotating employees with medical restrictions, lack of jobs to rotate to and a decrease in product quality were equally rated as the largest ‘limitations and obstacles’ when implementing job rotation in the companies’ facilities. The next highest
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M. Jorgensen et al. Table 1. Descriptive and statistical results from the job rotation questionnaire.
Job rotation survey questions
Mean
Median
95% CI
Significant difference*
Objectives for initiating job rotation (1 ¼ not at all important; 5 ¼ extremely important) Reduce incidence/cost of work-related injuries 4.45 5.0 4.40 – 4.49 Increase employee skill 4.21 4.0 4.17 – 4.25 Increase quality 4.00 4.0 3.92 – 4.08 Increase productivity 4.00 4.0 3.94 – 4.06 Reduce mental stress 3.97 4.0 3.92 – 4.03 Increase job satisfaction 3.95 4.0 3.90 – 4.00 Reduce absenteeism and/or turnover 3.34 3.5 3.27 – 3.41 Address government compliance issues 2.73 3.0 2.65 – 2.81
A B C C C C D E
Factors considered when devising job rotation schemes (1 ¼ not at all important; 5 ¼ extremely important) Reduction of risk factors for work-related 4.39 5.0 4.35 – 4.44 injuries Impact on production 4.08 4.0 4.03 – 4.13 Proximity of jobs 3.87 4.0 3.81 – 3.92 Jobs with similar experience level, training 3.63 4.0 3.58 – 3.68 or seniority Jobs that expose different body parts 3.47 4.0 3.39 – 3.55 Jobs with similar cycle times or production rates 3.42 3.5 3.36 – 3.49 Jobs with similar pay scales 3.18 3.0 3.11 – 3.25 Jobs that employees with medical restrictions 2.39 2.0 2.32 – 2.47 typically work Extent of methods used to develop job rotation schemes Supervisor driven (decision based on supervisor) Ergonomic job analysis Employee driven (direct input by the employees) Time studies Medical restrictions
A B C D E E F G
(1 ¼ not at all; 5 ¼ extremely) 3.89 4.0 3.84 – 3.95 3.81 4.0 3.74 – 3.88 3.29 3.0 3.24 – 3.34 2.89 3.0 2.82 – 2.97 2.46 2.0 2.38 – 2.54
Benefits realized from implementing job rotation (1 ¼ not at all; 5 ¼ very much) Increased skill of the employees 4.19 4.0 Decreased incidence/symptoms of work-related 4.08 4.0 injuries Increased employee morale or satisfaction 3.89 4.0 Increase in productivity 3.69 3.5 Increase in product quality 3.62 4.0 Reduced absenteeism 3.03 3.0 Reduced employee turnover 3.00 3.0
A A B C D
4.15 – 4.23 4.02 – 4.15
A B
3.84 – 3.94 3.64 – 3.75 3.54 – 3.70 2.96 – 3.09 2.93 – 3.07
C D D E E
Limitations and obstacles when implementing job rotation (1 ¼ not at all; 5 ¼ very much) Rotating employees with medical restrictions 2.18 2.0 2.12 – 2.25 Decrease in product quality 2.13 2.0 2.07 – 2.19 Lack of jobs to rotate to 2.11 1.5 2.04 – 2.17 Decrease in employee morale or satisfaction 1.97 2.0 1.92 – 2.02 Lack of job diversity 1.95 1.5 1.89 – 2.01 Different job pay scales 1.95 1.0 1.88 – 2.01 Lack of valid methods to determine jobs 1.81 1.0 1.75 – 1.87 to rotate to Increase in employee absenteeism 1.79 1.5 1.74 – 1.84 Union contracts 1.74 1.0 1.66 – 1.81 Increase in injury/illnesses 1.71 1.0 1.66 – 1.77 Increase in employee turnover 1.66 1.0 1.61 – 1.71
A A A B B B C C CD CD E
*Responses with same letter denotes no significant difference between mean response magnitude.
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rated ‘limitations and obstacles’ experienced included lack of job diversity, jobs with different pay scales and a decrease in employee morale or satisfaction. 3.3. Correlations between responses to survey questions and company demographics Correlation analysis results are shown in table 2. Company size appeared to be correlated with job rotation and an emphasis on injuries and illnesses. For example, there was a positive correlation between company size and the ‘objective’ of reducing the cost/incidence of work-related injuries (r ¼ 0.42) through utilizing job rotation, between company size and the ‘factors’ considered when developing job rotation (e.g. jobs that exposed different body parts, r ¼ 0.34), between company size and the extent of ‘methods’ used when developing job rotation schemes (e.g. time studies, r ¼ 0.37), and between company size and the ‘benefits’ realized from using job rotation (i.e. decreased incidence/symptoms of work-related injuries) (r ¼ 0.32). The highest correlation with company size was for ‘limitations’ of using job rotation, where the larger the company the greater perceived difficulty in using job rotation with employees with medical restrictions (r ¼ 0.51). Other significant correlations between ‘limitations and obstacles’ and the size of the company included a lack of job diversity (r ¼ 0.44). The number of years a company had been utilizing job rotation appeared to be negatively correlated with turnover and absenteeism. The longer the company had been utilizing job rotation, the less likely the objective was to reduce absenteeism or turnover (r ¼ – 0.48). Similarly, the longer job rotation had been in place, the less likely the perceived benefits were a reduction in absenteeism (r ¼ – 0.39) or a reduction in turnover (r ¼ – 0.43). Finally, the presence of a labour union was significantly correlated with issues related to pay scales and medical restrictions. A labour union present was significantly correlated with consideration of jobs with similar pay scales for inclusion in the rotation scheme (r ¼ 0.45), whereas the presence of a labour union was significantly correlated with the perceived job rotation implementation limitations of rotating employees with medical restrictions (r ¼ 0.33) and inclusion of jobs with different pay scales (r ¼ 0.45). 3.4. Job rotation survey repeatability Table 3 provides a summary of the repeatability of the responses to each of the job rotation questionnaire questions from the 25 companies. Overall, the answers for the two completions were identical 62% of the time, while 87.5% were within one Likert scale point, and 96.3% were within two Likert scale points. The overall average absolute error was 0.60 (or less than one Likert scale point) while the absolute errors for individual questions averaged 0.62 for objectives, 0.62 for factors considered, 0.52 for methods used, 0.53 for benefits and 0.69 for limitations. Thus, the majority of the time answers were well within one Likert scale point of each other, indicating good repeatability. For individual items, error rates ranged between 0.32 and 0.88 for ‘objectives’, 0.16 and 1.08 for ‘factors’ considered, 0.36 and 0.72 for ‘methods’ utilized, 0.08 and 0.84 for ‘benefits’ and 0.52 and 0.84 for ‘limitations’. The kappa statistics for individual items for the survey questions are shown in table 3. In general the kappa scores indicated marginal (0.1 to 0.4) to good (40.4) reproducibility (Landis and Koch 1977). The overall kappa statistic for questions about ‘objectives’ was
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Table 2. Pearson product moment correlation coefficients of job rotation survey responses to company demographics. Company size
Years utilizing job rotation
Union present
0.42 0.03 70.18 70.02 70.18 0.24 0.11 0.14
70.06 70.22 70.28 70.24 70.08 70.24 70.48 70.17
0.21 70.12 70.04 70.09 0.12 0.07 70.01 70.03
0.27 0.32 0.18 0.18 0.34 0.31 0.33 0.28
70.33 0.10 0.06 0.06 0.09 70.15 0.05 70.18
70.05 0.33 0.24 0.16 0.21 0.10 0.45 0.22
Extent of methods used to develop job rotation schemes Ergonomic job analysis Supervisor driven (decision based on supervisor) Employee driven (direct input by the employees) Time studies Medical restrictions
0.19 0.04 0.03 0.37 0.29
70.18 70.27 0.04 70.15 70.22
0.04 0.02 0.14 0.13 0.24
Benefits realized from implementing job rotation Increased skill of the employees Increased employee morale or satisfaction Decreased incidence/symptoms of work-related injuries Increase in productivity Increase in product quality Reduced employee turnover Reduced absenteeism
0.20 0.19 0.32 0.07 70.14 0.11 0.17
70.11 70.07 0.12 70.12 70.08 70.43 70.39
70.01 0.01 0.30 70.02 0.04 70.03 0.00
Limitations and obstacles when implementing job rotation Decrease in product quality Lack of jobs to rotate to Rotating employees with medical restrictions Decrease in employee morale or satisfaction Lack of job diversity Increase in injury/illnesses Increase in employee absenteeism Increase in employee turnover Lack of valid methods to determine jobs to rotate to Different job pay scales Union contracts
0.13 0.22 0.51 0.17 0.44 0.09 0.28 0.23 0.26 70.13 0.14
70.06 70.11 70.14 70.04 70.16 70.07 70.10 70.06 70.13 0.26 0.16
0.21 0.13 0.33 0.20 0.11 70.14 70.08 70.09 0.19 0.45 0.69
Job rotation survey questions Objectives for initiating job rotation Reduce incidence/cost of work-related injuries Increase employee skill Increase quality Increase productivity Reduce mental stress Increase job satisfaction Reduce absenteeism and/or turnover Address government compliance issues Factors considered when devising job rotation schemes Impact on production Reduction of risk factors for work-related injuries Proximity of jobs Jobs with similar experience level, training or seniority Jobs that expose different body parts Jobs with similar cycle times or production rates Jobs with similar pay scales Jobs that employees with medical restrictions typically work
Shaded cells indicate statistically significant correlations (p 4 0.05).
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Job rotation in Midwest manufacturing companies Table 3. Reliability results for job rotation survey questions.
Percent identical
Percent within 1 Likert point
Percent within 2 Likert points
0.32 0.44 0.68 0.64 0.64 0.52 0.88 0.80
76 76 48 52 60 64 44 64
96 88 80 92 84 92 72 88
100 100 88 96 96 100 96 88
1.08 0.92
44 88
92 100
100 100
0.68 0.64
64 60
80 84
96 100
0.42 0.64 0.16 0.42
72 40 44 52
92 68 68 96
96 92 88 96
0.68 0.44
76 56
96 88
96 96
0.72 0.36 0.40
68 52 80
88 92 92
96 96 96
0.49 0.25 0.64
0.60 0.52 0.71
68 52 72
96 88 96
100 96 96
0.32 0.28 0.46 0.48
0.84 0.08 0.20 0.67
48 44 52 60
92 84 84 88
100 92 92 96
Limitations and obstacles when implementing job rotation Decrease in product quality 0.30 Lack of jobs to rotate to 0.53 Rotating employees with medical restrictions 0.51 Decrease in employee morale or satisfaction 0.42 Lack of job diversity 0.47 Increase in injury/illnesses 0.12 Increase in employee absenteeism 0.20 Increase in employee turnover 0.17 Lack of valid methods to determine jobs to rotate to 0.39 Different job pay scales 0.45 Union contracts 0.63
0.52 0.67 0.84 0.76 0.71 0.72 0.68 0.58 0.67 0.76 0.64
52 52 56 64 64 64 60 60 60 56 76
84 80 80 92 80 76 76 84 84 80 84
96 92 96 100 92 84 92 88 92 96 96
Job rotation survey questions Objectives for initiating job rotation Reduce incidence/cost of work-related injuries Increase employee skill Increase quality Increase productivity Reduce mental stress Increase job satisfaction Reduce absenteeism and/or turnover Address government compliance issues
Kappa
Average absolute error
0.58 0.40 0.47 0.38 0.43 0.43 0.35 0.51
Factors considered when devising job rotation schemes Impact on production 0.28 Reduction of risk factors for work-related 0.80 injuries Proximity of jobs 0.42 Jobs with similar experience level, training or 0.35 seniority Jobs that expose different body parts 0.75 Jobs with similar cycle times or production rates 0.15 Jobs with similar pay scales 0.23 Jobs that employees with medical restrictions 0.61 typically work Extent of methods used to develop job rotation schemes Ergonomic job analysis 0.73 Supervisor driven (decision based on 0.27 supervisor) Employee driven (direct input by the employees) 0.62 Time studies 0.61 Medical restrictions 0.84 Benefits realized from implementing job rotation Increased skill of the employees Increased employee morale or satisfaction Decreased incidence/symptoms of workrelated injuries Increase in productivity Increase in product quality Reduced employee turnover Reduced absenteeism
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0.53, about ‘factors’ considered was 0.75, about ‘methods’ used was 0.67, about ‘benefits’ was 0.73 and about ‘limitations’ was 0.40. Overall, the survey questions were found to have good reproducibility. 4. Discussion The online questionnaire method was found to be a repeatable method to survey characteristics of job rotation usage and perceptions of benefits and limitations of its use. The kappa statistics in general were good (4 0.4) for the question categories and individual items, with 62% of the items having identical scores on both surveys. The results of this survey suggest that the use of job rotation may be increasing in popularity. Of the companies providing information regarding their job rotation utilization, 42.7% indicated that they utilized some form of job rotation. This is greater than that found by Gittleman et al. (1998) (24.2% of companies with 50 or more employees in non-agriculture establishments) or Dempsey (2002) (23% of lifting jobs in the industrial and service sectors across the United States). It also appears that the implementation of job rotation in many companies is relatively recent, as the median time that job rotation had been used in these facilities was 5 years, and several other companies that were contacted were also contemplating implementing job rotation. However, these results also suggest that job rotation may be being used as a permanent intervention strategy, rather than as an interim control strategy until engineering controls can be developed and implemented, contrary to the recommendations from NIOSH and OSHA. Given that the median duration of use of job rotation was 5 years, and more than 83% of the companies in the survey had used job rotation for more than 2 years, it appears that few companies stop using job rotation once it has been implemented at their facility. The major ‘objective’ (to reduce incidence/cost of work-related injuries) and ‘factor’ considered (reduction of risk factor exposure) when implementing job rotation schemes were consistent with the objectives identified by NIOSH and OSHA. The second highest considerations (related to objectives and factors considered) for job rotation were production-related, including increasing the skill of the employees and the impact that job rotation would have on production, consistent with some of the personnel management objectives indicated by Cheraskin and Campion (1996). The findings from this survey from individuals responsible for safety and health in the manufacturing companies suggest that, although the motivations for developing job rotation may have been initially related to employee safety and health, the perceived benefits of increased employee skill was more apparent than the effect on safety and health outcomes. Rotating individuals through jobs has the potential to increase exposure to risk factors to some employees if the jobs are not selected appropriately (Triggs and King 2000, Frazer et al. 2003). Triggs and King (2000) suggested that valid methods be used to identify jobs for rotation schemes, including methods such as the Strain Index (Moore and Garg 1995) and the NIOSH Lifting Equation (Waters et al. 1993). Although little to no guidance has been published describing how to use ‘valid’ methods to determine effective job rotation schemes, ‘lack of valid methods to determine jobs to rotate to’ was not considered to be much of a limitation when implementing job rotation. Additionally, the methods most utilized to determine the job rotation schemes consisted of decisions by supervisors as well as input from ergonomic job analyses. The median duration of time on a job before rotating to the next job was 2 h, which is consistent with the duration of the time between naturally occurring breaks in the work shift (e.g. rest breaks, lunch). Thus, it appears that supervisors’ opinions regarding which jobs to rotate to are given as
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much weight as ergonomic job analyses, and the decision when to rotate may be based on convenience (e.g. rotate after a break) rather than duration of exposure to risk factors. This survey did not allow for elaboration on the types of ergonomic job analysis techniques that were used. Thus, one might question the validity of the job rotation scheme in terms of exposure to risk factors due to not knowing the extent of the ergonomic analysis methods used, as well as the reliance on supervisor decisions. This merits further research regarding the types of ergonomics analyses utilized, as well as the quantification of exposure to WMSD risk factors in the current job rotation schemes to determine the real effectiveness of job rotation in controlling WMSDs. One of the major limitations identified for implementing job rotation, which has not previously been reported in the research literature, was rotating employees with medical restrictions. Correlation analyses indicated that the larger the company the higher the perception that this was a limitation for job rotation, and the presence of a labour union was also associated with a higher perception that this was a limitation. The presence of individuals with medical restrictions may have also increased the perception that there was a lack of jobs to rotate to, as the two were positively correlated (r ¼ 0.46, p ¼ 0.003). This limitation may become an increasingly difficult situation to overcome as the US Bureau of Labor Statistics (2004) data suggest that although there is a decreasing trend for injuries and illnesses that result in lost work days in private industry establishments in the USA, there is an increasing trend for the number of injuries and illnesses that result in restricted work days (figure 1). Thus, more individuals are returning to work from injuries and illnesses with work restrictions that would potentially limit their capability to perform all jobs in existing job rotation schemes. Other important perceived limitations for the utilization and implementation of job rotation were the presence of labour unions and a decrease in product quality. Other investigators have also observed resistance from labour unions to job rotation due to issues related to differences in pay scales from jobs in the rotation schemes, which is consistent with the findings from the present survey (Hazzard et al. 1992, Triggs and King 2000). Perceived limitations of implementing job rotation due to decreases in product quality, however, have not been previously identified in the job rotation research
Figure 1. Trends for occupational injuries and illnesses resulting in lost work days and restricted work days from 1975 to 2002 for private industry establishments in the United States (Bureau of Labor Statistics 2004).
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literature in a manufacturing setting. Cheraskin and Campion (1996) indicated that job rotation may increase the workload and decrease productivity for the rotating employee and other employees, and increase costs due to errors that employees often make while learning a new job. However, these authors were referring to employees in management track professional positions, not production positions in a manufacturing setting. Thus, although there may be benefits to job rotation in terms of increased skill of the employees, it may be that there will also be training issues related to product quality that need to be overcome before the job rotation scheme is running smoothly and effectively with regard to production issues. The results of this study should be considered in the light of methodological limitations. A response bias may be present regarding the objectives and factors considered for job rotation in that the respondents contacted were individuals within the company responsible for safety and health, and the fact that objectives regarding injury prevention and risk factor exposure were rated the highest. Additionally, the results are based on the perceptions of the respondent, and no effort was made for this aspect of the study to quantify the results, such as actual benefits or limitations. Some companies (n ¼ 38) failed to complete the survey after they had initially agreed to complete it. Based on follow-up phone conversations, it appeared that lack of time was the limiting factor in not completing the survey, not lack of willingness to share information. Another bias may have risen from the web-based survey. While almost all the companies contacted had access to the Internet, some participants may not have completed the survey due to it being online. However, all efforts were made to assure them they could complete the survey on paper. Another source of potential bias is the companies that provided no information about current or previous status of job rotation. Whilst every effort was made to gather some information, several companies would not provide any information. Most of these companies indicated they did not want to provide any information at all, or that it was against company policy. These companies had similar sizes to (and the SIC codes were similar to) those that participated in the study so it is very likely the potential non-participation bias was minimal. 5. Conclusions Several conclusions regarding the practice of job rotation can be drawn from this study. First, from the sample of 178 local manufacturing firms that provided responses, the job rotation survey found that 42.7% of these manufacturers use job rotation in their manufacturing processes, which is higher than previous estimates. Second, from those companies that used rotation and responded to the survey, the length of time that job rotation had been used suggests that job rotation may be being used on a permanent basis as part of their production process, rather than as a temporary administrative control as suggested by NIOSH and OSHA. Third, decisions by supervisors are considered as equally important as the use of ergonomics analyses to decide which jobs to include in the job rotation scheme. Fourth, rotating individuals with medical restrictions, decreases in product quality and a limited number of jobs to rotate to were identified as the top limitations when implementing job rotation. Fifth, although employee safety and health concerns appeared to be the highest rated consideration for implementing job rotation, production-related aspects of increased employee skill was perceived to be the largest benefit from job rotation. Finally, although reduction to risk factors for work-related injuries was considered the most important factor when devising job rotation schemes, it is unclear if in fact reduction of exposure is actually achieved, which merits further research.
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