10 Questions to Consider When Upgrading to AEM 6.1

The new version of the platform includes some significant changes to architecture behind the scenes, meaning that it is not a “flip the switch” upgrade. While the upgrade comes with some significant improvements, such as Sling and OSGi version upgrades and new features like touch UI, careful planning is still required to help ensure success.
10 Questions to Consider Before Upgrading to AEM 6.1

When creating a plan for the upgrade, here are some of the questions they had to consider:

1. Would they use TarMK or MongoDB?
2. Would they upgrade to Java8?
3. Would they do a new, clean install or upgrade in place?
4. Would they upgrade to AEM 6.0 or AEM 6.1?
5. How would they handle all the API version updates?
6. How would teasers work in 6.0?
7. How would they handle the jQuery upgrade — how far would they go to clean up old jQuery?
8. Would they use Google guava 15 or guava 17?
9. Would they use classic UI or upgrade to the new touch UI?
10. When would they start using Sightly?

For their upgrade, this particular client decided to do a “bare bones” upgrade to AEM 6.1, working with a minimal viable product to implement the upgrade, beginning with a jQuery upgrade and component clean up. They decided to go ahead and upgrade to Java8 and to leave new personalization efforts, Campaign, and the new Touch UI to be implemented once the initial upgrade was complete.
Once they’d made those decisions, there were still a few other items to address before moving forward.

1. Check the Adobe docs
2. Check the upgrade scenarios
3. Check the service pack info
4. Check performance optimization
5. Try things — use data to decide your path
6. Plan the performance testing
7. Assess risks

Since they had previously upgraded to 5.6.1, they were able to use lessons learned during that process to help ensure this upgrade went a lot more smoothly. For example, during the upgrade to AEM 5.6.1, they’d experienced a significant performance fail — they’d missed doing performance testing on the author's side of the platform. So heading into the AEM 6.1 upgrade they made sure to keep that previous upgrade experience in mind.

Source: https://www.blueacornici.com/blog/upgrading-aem-6-1/