Currently, farrowing crates dominate indoor pig farrowing in the UK (~ 60% of herds). Such systems raise welfare problems due to close confinement of the sow. Although, many alternative housing systems have been developed in different countries, no commercially viable/feasible option has emerged for large-scale units. We have reviewed current scientific and practical knowledge of farrowing systems to identify alternative systems, their welfare and production potential. Our aim is to establish acceptable trade-offs between profit and welfare within alternative farrowing systems using linear programming, hence designing high welfare but commercially viable alternatives to the farrowing crate. System-specific results of interactions between welfare components and financial performances have been analysed and presented in this paper.