A participative methology was developed in which farm managers decomposed their process of decision making in Precision Agriculture (PA) into brief secision statesments along with associated information requirements. The methodology was first developed on a university research farm in Denmark and further revised during testing on a number of research and commercial farms in Indiana, USA. Twenty-one decision analysis factors were idebfied to characterise a farm manager's decision-making process. Then a general data flow diagram (DFD) was constructed that describes the information flows "from data to decision". Illustrative examples of the model in the form of DFDs are presented for a strategic and an operational decision. The model was validated for a range of decisions related to operations by three university farm managers and by five commercial farmers practicing PA for cereal, corn and soybean production in Denmark and in Indiana, USA.