Theses and Dissertations

Issuing Body

Mississippi State University


Crumpton-Young, Lesia

Committee Member

Adams-Price, Carolyn

Committee Member

Bullington, Stanley

Committee Member

Smyer, William

Date of Degree


Document Type

Dissertation - Open Access


Industrial Engineering

Degree Name

Doctor of Philosophy


College of Engineering


Department of Industrial Engineering


Demographics indicate that the United States and many other industrialized nations are currently experiencing what is called the ¡°graying¡± of the workforce (Hayslip & Panek, 1993). Today the majority of the workers in many companies are in the age groups of 40-44 and 45-49 years. However, by the year 2010, the largest proportion of workers will probably be in the age groups of 55-59 and 60-64 years (Ilmarinen, 1995). Thus, a growing concern of employers in the near future will be the assignment of older workers to specific job tasks and responsibilities (Williams & Crumpton, 1996) as well as other issues pertinent to the employment of older workers. As workers age they typically experience physiological and psychological changes which must be estimated to minimize the mismatch between their capabilities and job demands as well as to prevent work related injuries such as over exertion injuries. Early identification of declines in work ability and implementation of ergonomic interventions are key to sustaining older and more experienced workers in the workplace (Williams et al., 1996). If preventive measures are not taken, older employees are likely to experience a decline in work capacities (Ilmarinen, 1994). Therefore, reliable and valid measures of one¡¯s ability to perform physical work activities are essential for preventing work-related injuries. Hence, the focus of this research project is to develop a diagnostic tool that can be used by employers to estimate their workers¡¯ ability to perform daily work activities. Specifically, the Williams Work Estimator (W2E) is designed to provide information concerning workers¡¯ ability to perform physical work activities such as lifting, lowering, pushing, pulling, etc. A field research study involving 32 employees at a beer distribution warehousing facility was conducted to evaluate the following attributes of the W2E: (a) test-retest reliability, (b) concurrent criterion validity, and (c) predictive validity. Test-retest reliability of the W2E was assessed using Pearson correlation coefficients. The overall correlation coefficients obtained on both the task evaluation (.64) and the self-evaluation (.58) were near minimal acceptable levels (.60 or greater) for each job task evaluated. In addition, the W2E ranged from 50 to 100% accurate when identifying persons who had experienced a work-related injury within the past year. Findings of this research study suggest the W2E represents a promising new tool for assessing work capability and deserves further study to improve reliability and validity.