Probably the most important way to improve quality is to strengthen quality management processes throughout the design process – the principle of building it right the first time, instead of spending more effort on detecting and correcting errors. Just extending the cycle without changing quality management will be very unlikely to lead to any improvement. But better quality management does not mean making the cycle longer, so it is unlikely that the cycle length is relevant, as evidenced by Apple’s only real two-year development cycle with Mac OS X 10.4 Tiger.
This is true if you’re talking about the quality of your next major release when it̵
With the annual release cycle, large versions no longer reach that level of sophistication because development stops when Apple moves on to the next new release. And developers are forced to upgrade earlier because exploiting the latest SDK requires the new version of Xcode, which requires a current version of macOS. You can now choose between the still buggy macOS 10.15.7 and the upcoming macOS 11.0.0, which will have issues outside the port, as all releases do. These are not good choices.
For the first public releases of Mac OS X, Apple adhered to a development cycle of well under one year per release. Beginning with the Panther release in 2003, Mac OS X settled in something closer to a gap between eighteen months x.0 public releases, with a long exception for Tiger. So, with Mountain Lion in 2012, Apple stated that the intention was to start releasing a new version of OS X every year; Mountain Lion had a shorter cycle than its predecessors, but it was still longer than any release after.
In all three epochs of MacOS development cycles, you will find versions that are legendary for their improvement, and those that are completely opposite.
What are the recent releases? macOS 10.14.6 is better than any 10.15, but it retains the share of editions. macOS 10.13.6 has a common Mail IMAP sync crash that was never resolved. macOS 10.12 was generally a rough release and retained severe PDF errors throughout its life. My recollection is that macOS 10.11.6 was probably the best since 10.6.8.
Stay up to date by subscribing to the RSS feed for comments for this post.