  The Atacama Large mm and sub-mm Array (ALMA) radio observatory is one of the
world's largest astronomical projects. After the very successful conclusion of
the first observation cycles Early Science Cycles 0 and 1, the ALMA project can
report many successes and lessons learned. The science data taken interleaved
with commissioning tests for the still continuing addition of new capabilities
has already resulted in numerous publications in high-profile journals. The
increasing data volume and complexity are challenging but under control. The
radio-astronomical data analysis package "Common Astronomy Software
Applications" (CASA) has played a crucial role in this effort. This article
describes the implementation of the ALMA data quality assurance system, in
particular the level 2 which is based on CASA, and the lessons learned.
