Sony recently updated its Tablet S product from Android 3 to Android 4. The latest version of Android, codenamed Ice Cream Sandwich (ICS), was released in November. According to Jean-Baptiste Queru, an Android platform engineer at Google, the five-month wait is “very reasonable,” in light of the complexity involved in moving from Honeycomb to ICS.

Queru also acknowledged that Google has yet to roll out the ICS update to some variants of its own flagship Nexus device. He attributed the issue to delays caused by the network operator approval process. The remarks, which were posted on Google+, have drawn scrutiny from Android enthusiasts and developers who are concerned about Android version fragmentation and the lack of predictable update availability in the Android ecosystem.

At Google I/O last year, Google’s Andy Rubin announced a new initiative to streamline the update process. The search giant said it would collaborate with handset manufacturers and mobile carriers to come up with a strategy for making Android updates more timely and predictable.

At the time, Rubin said that the effort was still at an exploratory stage and that it hadn’t produced any actual solutions yet. Google hasn’t issued any further remarks on the status of the update initiative. The update situation arguably hasn’t improved much since that announcement.

Ultimately, there might not be much that Google can do to address the issue. Critics of the Android update model often compare it to Apple’s approach with iOS, where new versions of the operating system are rolled out to old devices at the same time that they launch on new devices.

Apple has a much smaller range of devices to contend with, however, compared to the breadth of the Android ecosystem, which has a more diverse spectrum of hardware. It’s worth noting that Microsoft has also encountered update difficulties with its own Windows Phone operating system.

One thing that Google could do to help simplify the process is to start developing Android in the open instead of developing it behind closed doors and doing a code drop for each major release. Easier access to the code while it’s in development would allow handset makers to do continuous integration and give them a head start on addressing challenges they need to overcome to align their own customizations with new versions of the platform.