The civil aircraft industry often assembles large deformable aluminium components within the fuselage and wing structures. Part-to-part assembly of these compliant components regularly causes difficulties associated with dimensional variations. This paper describes a methodology to predict overall deformation between the alignment of the rib foot and the skin panel. The assembly operations and conditions encountered on the real production jigs were conducted under simulated laboratory conditions. A table method for prediction was developed to reduce uncertainties in positioning between the skin panel and rib foot. Finite element model of the rib was created to further enhance the prediction method. Results obtained from the predicted method were evaluated against real factory data. The validation performed against the assembly plant showed good performance of the prediction method in forecasting the positional variations occurring during the simulation of the assembly. The prediction method was, therefore, proven to be reliable.