Work ability is a dimension that evaluates whether an employee is able to do his/her job in the present and in the future, in relation to the demands of the job itself, to the work environment and to his/her own mental and physical resources. Assessments of health and capacity form the basis for work ability measurement, as much as professional knowledge and competence (skills), values, attitudes, and motivation, the type of work and the working environment.
Working conditions that are physically demanding or that imply low job control or that are done in a hindering working environment decrease the work ability of a person.
Work ability can be assessed using the Work Ability Index (WAI), a questionnaire developed by the Finnish Institute of Occupational Health (FIOH) in the 1980s and based on employees’ self-assessment of their current work capacity.
The basic scientific question was how long employees and employers are able to work and to what extent being able to work depends on the work content and on job demands. The concept of work ability was later adopted in various other European and Asian countries .
Awareness of the factors that either at person or at environmental level determine work ability, enables scientific action to be taken in order to increase employees’ work participation or to improve work productivity.
 Ilmarinen J., Work ability – a comprehensive concept for occupational health research and prevention, Scandinavian Journal of Work, Environment & Health, VOL. 35(1), pp. 1-5, 2008.