A method for evaluating the quality of data collection in a manufacturing environment is provided. Said data are intended to be analyzed by a process control system. The method comprising the following steps (A) collecting raw data according to a Data Collection plan specifying, and for each data item, a sampling time reference indicating at which time interval it is expected, and associating to each collected data item a timestamp indicating its actual collection time, (B) for at least a part of the raw data included inside a predetermined window, determining a Data Collection Quality Value (DCQV) by: (a) reading the timestamps; (b) computing at least one quality indicator value from the relationship between each timestamp and the corresponding time reference, wherein a shift represents a malfunction of the equipment or of the data collection system; (c) after steps (b) and (c) have been performed for all data items, computing a single data collection quality value (DCQV) indicator for said time window. Application to data qualification for analysis and equipment qualification e.g. in a semiconductor fab.