The processes involved in the KM3NeT data processing chain can be grouped into a few main categories. Although the ordering of these categories is not strictly hierarchycal from the point of view of data generation and processing, in the context of a general discussion one could safely assume that a hierarchycal nature exists between them. From bottom to top, these categories would be, data acquisition, detector calibration, event reconstrucion, simulations and finally scientific analyses based on the data processed in the previous categories. The quality of the scientific results produced by KM3NeT will be affected by the performance of the different processes involved in the lower levels of the data processing chain. In order to implement a complete and consistent set of data quality control procedures that span the whole data processing chain, it is required to have a complete, unambiguous and documented strategy for data processing at each of the aforementioned process categories. This includes the setting of data quality criteria which should be initiated at the highest level of the data processing chain, and propagated towards the lowest levels. For each of the aforementioned categories there exists a working group within the KM3NeT collaboration. It therefore corresponds to each of these working groups to develop the working group objectives and procedures according to the scientific needs of KM3NeT. Currently such a documented strategy does not exist for any working group. It has therefore not been possible to develop a full strategy for data quality control. Nevertheless, there have been copious software developments devoted to quality control along the different stages of the data processing chain. In the following, a description of quality control tools and procedures is given. This description could be conceived as an incomplete prototype for a data quality plan.
