Imprecise Description of Limits
A browse of Microsoft’s documentation for Planner limits caused my brow to furrow. On the surface, the limits are precise and cover both plans and tasks. The problem is with the words used to describe limits.
For example, we learn that a plan can have up to 2,400 active tasks. Presumably, these are tasks in the not started and in progress status, but Microsoft doesn’t make this clear. I infer this meaning by reference to the limit for tasks in a plan, 9,000, meaning that 6,600 tasks can be closed to allow room for the 2,400 active tasks. Again, Microsoft is mute on the topic.
Twenty-four hundred active tasks is not a very large number. Indeed, 2,400 and 9,000 both seem arbitrary limits in a suite where it’s common to store hundreds of thousands of messages or documents. It might seem that 9,000 tasks is more than sufficient for even the most comprehensive plan, but some plans do span large numbers of tasks.
Indeed, the first time I looked at the documented Planner limits, I was worried that the plan the Office 365 for IT Pros writing team use to synchronize and track notifications from the Microsoft 365 message center was getting close. Fortunately, we close tasks as their subject matter appears in a book update, so the current overall total of 2,077 (Figure 1) still has room to grow.
The maximum number of buckets in a plan is 200. The layout used by Planner resembles a Kanban format where the cards on the board help people to visualize work. Usually, the columns on the board represent a workflow stage, but Planner buckets can be used for anything, and 200 appears to be more than sufficient.
We also learn that an individual user can own up to 200 plans. By owner, I assume that Microsoft means that the user is the owner of the group which owns the plans (a group used by a team can have multiple plans). Although 200 seems a lot, I could see how the limit might be reached if an account is used to create a lot of groups or teams.
Up to 300 plans can be shared with a user. I do not know what this means. Perhaps it’s where an account is a member of a plan. But then Microsoft documents that up to 100 users can be shared with a plan? And there can be up to 10 contexts on a plan. I have no idea what either limit refers to. Thankfully, I don’t seem to have encountered either limit in the six years that I’ve used Planner. Or maybe I have and I haven’t noticed.
Moving on to the Planner limits for tasks, the fundamental building blocks of plans, we find that a task can be assigned to a maximum of eleven people. Most tasks are assigned to one or two team members, so eleven seems sufficient, even if the limit seems a tad arbitrary. A task can include a set of checklist items used to describe individual elements which are part of the task. There can be up to 20 checklist items in a task.
An individual user can create up to 20,000 tasks spread across all the plans they are a member of. They can be assigned a maximum of 3,000 tasks, but there’s no clarification whether this number includes completed tasks or just active tasks.
Then we come to some oddities that Microsoft doesn’t explain. There can be ten references on a task. This might refer to the number of attachments that users can add to tasks, but the Planner UI restricts this to nine. The limit doesn’t refer to comments: I know of tasks with more than 20 comments, each of which is transmitted by email to plan members.
References on a task is a mystery and so is “maximum user data count in user details.” Although I have no idea what this limit is, there can be up to ten of whatever they are for a task.
Apart from Microsoft wanting to keep the Planner limits low enough to be useful but not high enough to threaten Microsoft Project, I can’t understand why some of these limits are not higher, especially considering that a team can have multiple plans attached to channel tabs.
Helpfully, Microsoft closes the page by telling us that the Planner limits can be raised or lower at any time, which is nice to know. It would be even better if they documented what each limit meant in a practical sense. However, given the pace at which things happen inside Planner (like creating the ability to move tasks between plans in other groups or creating a way to block users from deleting tasks, I won’t hold my breath.
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