The purpose of this study was to designing and testing a model of some precedents and outcomes of work ability index. The variables in the model were arranged in three parts: precedents (personal resources, life management strategies and job-related stressors), outcomes (health- related quality of life and job performance) of work ability index. The participants were 320 employees of NISOC, in Ahvaz, who were selected by stratified random sampling method. Of this sample, 72 percent were men and average age was 41 years. Instruments used in this study were work ability index, life management strategies, general self-efficacy, optimism, coping skill, effort-reward imbalance, demand-control, health related quality of life and job performance questionnaires. Fitness of the proposed model was examined through structural equation modeling (SEM), using SPSS-16 and AMOS-16 software packages. The indirect effects were tested using the bootstrap procedure in Preacher and Hayes (2008) SPSS Macro program for mediation. Findings indicated that the proposed model fit the data. Better fit and more meaningful results obtained by correlating the errors of two paths. All of indirect effects were significant.
