A method for obtaining a range of fingerprints defining the quality of a freeze-drying process, comprising the steps of: i) providing a product to be freeze dried; ii) fixing the temperature and pressure set points for the freeze drying process; iii) defining a set of experiments by statistical design of experiments (DoE) for the freeze drying process in order to introduce variability in the process and to study their influence on the quality of the obtained freeze dried product; iv) performing a freeze drying process of the product of step i) for each one of the experiments defined in step iii) using a freeze dryer; v) obtaining a dataset of pressures and temperatures from the freeze dryer and, optionally, from at least one probe measuring additional information about the process or the product, wherein the dataset of pressures and temperatures from the freeze dryer comprises at least one combined parameter; vi) removing noise intrinsic to the measurements from the dataset in order to obtain smoothed data by using computational methods, and scaling the smoothed data; vii) performing a first multivariate analysis on the smoothed and scaled data by using Principal Component Analysis to obtain a first set of principal components; viii) analysing the first set of principal components in order to select a set of parameters by eliminating parameters with loading values close to zero and parameters having the same loading value as another parameter, and carrying out a second multivariate analysis by using PCA on the selected parameters to obtain a second set of principal components; ix) selecting the number of principal components explaining a variance equal to or higher than 95% of the total variance of the dataset to obtain a fingerprint of the freeze drying process for each one of the experiments carried out in step iii); x) analysing the quality of the freeze dried product obtained by each one of the experiments carried out in step iii) in order to see if the product is within specifications; and xi) selecting the fingerprint of the process yielding the finished product with the best analytical profile, and the fingerprint of the process carried out at the highest temperature and pressure yielding a product within specifications, both fingerprints defining a range of fingerprints in which a specific product batch will be within specifications. i) providing a product to be freeze dried; ii) fixing the temperature and pressure set points for the freeze drying process; iii) defining a set of experiments by statistical design of experiments (DoE) for the freeze drying process in order to introduce variability in the process and to study their influence on the quality of the obtained freeze dried product; iv) performing a freeze drying process of the product of step i) for each one of the experiments defined in step iii) using a freeze dryer; v) obtaining a dataset of pressures and temperatures from the freeze dryer and, optionally, from at least one probe measuring additional information about the process or the product, wherein the dataset of pressures and temperatures from the freeze dryer comprises at least one combined parameter; vi) removing noise intrinsic to the measurements from the dataset in order to obtain smoothed data by using computational methods, and scaling the smoothed data; vii) performing a first multivariate analysis on the smoothed and scaled data by using Principal Component Analysis to obtain a first set of principal components; viii) analysing the first set of principal components in order to select a set of parameters by eliminating parameters with loading values close to zero and parameters having the same loading value as another parameter, and carrying out a second multivariate analysis by using PCA on the selected parameters to obtain a second set of principal components; ix) selecting the number of principal components explaining a variance equal to or higher than 95% of the total variance of the dataset to obtain a fingerprint of the freeze drying process for each one of the experiments carried out in step iii); x) analysing the quality of the freeze dried product obtained by each one of the experiments carried out in step iii) in order to see if the product is within specifications; and xi) selecting the fingerprint of the process yielding the finished product with the best analytical profile, and the fingerprint of the process carried out at the highest temperature and pressure yielding a product within specifications, both fingerprints defining a range of fingerprints in which a specific product batch will be within specifications.