In the scientific literature several attempts have been made to systematically assess the overall welfare-status of animals in relation to housing and management. This paper reviews assessment tables and schemes that have been constructed to this end. These tables and schemes have a tabular format that allows an assessment of housing systems using a list of welfare-relevant attributes (properties of the housing system). Rather than identifying deficits, the focus of this review is on finding positive recommendations for the purpose of developing a method for overall welfare assessment (OWA) on a scientific basis. The main recommendation is to use the tabular format as representation formalism for OWA. The concept of linked tables provides the key to performing OWA on a scientific basis in an explicit and systematic way.
Bracke, M. B. M., Spruijt, B. M., & Metz, J. H. M. (1999). Overall animal welfare assessment reviewed. Part 2: Assessment tables and schemes. NJAS wageningen journal of life sciences, 293-305.