The first part of the paper is devoted to a brief survey of the firm ineficiency literature. This concept is defined by the distance between the observed production level and the maximum attainable level which could be reached in case of optimal use of inputs, i.e. the frontier production function. In the literalure many parametric and nonparametric approaches are developed. In this paper we propose a nonparametric method, Data Envelopment Analysis (DEA) based on linear programming. This approach is implemented using a cross-section of 107 French pigfarms. DEA permits a classifcation of the farms occording to their efficiency. Half of them are elficient with a score equal to l. The first results show,that ineficiency is linked to bad level of education which characterises the oldest farmers. A more complete approach needs a larger sample to compute both scale eficiencv and lechnical eficiency.