Nowadays sustainability has become one of the major topics of interest in farming systems research. Farming systems sustainability is analyzed in this work by introducing the concept of technical sustainability, defined here as the ability of a biological production system to make an efficient use of the available resources on field level with the main goal to maximize its economic output given a set of uncontrolled biophysical constraints. This concept is developed and applied to the agricultural production area of the Mantaro Valley (Peru). Through fortnightly visits, data on biophysical characteristics of the crops on selected production fields were collected without taking part in the decision process of the growers to manage their crops. Afterward, by applying a multivariate exploratory data method, principal component analysis, it was possible to establish technical efficiency gradients for the tested data. The capabilities of such type of analysis are explored by studying two types of standardization of the collected data. The biplot graphical output that can be built upon the results of the analysis represents an extra powerful feature to interpret the outcome of the analysis. © 2012 Copyright Taylor and Francis Group, LLC.