Sitecore out-of-the-box does not come with a feature built-in that would allow you to setup bi-directional relationship between items. Hence, I have decided to write my own solution and share it with the community.
John has done a great job describing the various ways how item updates can be intercepted in the following post.
The two options that I identified as the most viable were either write a custom Sitecore handler for the OnItemSaved event (option 1) or write a rule (option 4). The advantages for the rule mentioned by John convinced me that this would be the best option. Here are some of the reasons summarised:
- Control logic and parameters through UI from content authoring environment
- Separation of concerns: Rule condition under which the rule runs is part of the configuration
- Rule only executes on the database that it is configured