A two-stage stochastic programming model for scheduling replacements in sow farms

• Published in: TOP Vol. 17; no. 1; pp. 171 - 189
• Main Authors: Rodríguez, Sara V., Albornoz, Victor M., Plà, Lluís M.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2009
• Subjects: Business and Management; Economic Theory/Quantitative Economics/Mathematical Methods; Economics; Finance; Industrial and Production Engineering; Insurance; Management; Operations Research/Decision Theory; Optimization; Original Paper; Statistics for Business; Sow herd management; Replacement; 90C15; Planning; 90B50; Stochastic programming
• ISSN: 1134-5764; 1863-8279
• DOI: 10.1007/s11750-009-0087-2

This paper presents a formulation and resolution of a two-stage stochastic linear programming model with recourse for sow farms producing piglets. The proposed model considers a medium-term planning horizon and specifically allows optimal replacement and schedule of purchases to be obtained for the first stage. This model takes into account sow herd dynamics, housing facilities, reproduction management, herd size with initial and final inventory of sows and uncertain parameters such as litter size, mortality and fertility rates. These last parameters are explicitly incorporated via a finite set of scenarios. The proposed model is solved by using the algebraic modelling software OPL Studio from ILOG, in combination with the solver CPLEX to solve the linear models resulting from different instances considered. The article also presents results obtained with previous deterministic models assessing the suitability of the stochastic approach. Finally, the conclusions drawn from the study including an outlook are presented.