The completion probability is calculated by running a monte carlo simulation on the planned items given the planned work item sequence and their estimates.
If you have not specified a minimal or maximal estimate, the simulation uses half and double the estimate for the minimal and maximal values respectively.
It considers the work environment to calculate the remaining work time until the end of the iteration of the respective owners.
Using this information, the Completion Probability indicates how probable it is for each work item to be resolved within the iteration. The due date is not considered.

However, the if the due date is before the scheduled resolution time, a warning decoration is added to the leftmost column.

As for the "Plan For" menu, there is a set of predefined entries which we show dynamically. If you have only one work item already planned with an estimate of one hour, the end of your planned work queue is in an hour from now.
Because you can only place the work items in the planned sequence, we do not show "Next Week", as the work item can only be appended to the end of the list and is therefore scheduled for today.
Note that the "Plan For" menu entries are used as an indication where to insert the work items only. if you select "Next Week", it tries to insert the work item in a place in the sequence that it appears as planned for "Next Week".
However, this is not always possible, for example if you have only one work item planned that is estimated five weeks. In this case, planning it for next week is not possible as the already planned work item cannot be split up.
Enhancement 63920 tracks the effort to implement a more flexible scheduling.

--
MikeS
Jazz Agile Planning team

miwalker wrote:

How does RTC determine the Completion Probability in the Risk
Assessment Plan?


I have 2 work items that were both accepted by the Owner in the My
Work tab and planned to start "Later this week".

The first one has an estimate of 5 weeks and due on Aug 5th. This one
appears in red as a risk. It's Completion Probability is .334

The 2nd work item has an estimate of 1 week and a due date of Aug 3rd,
yet it's Completion Probability is 1.0 and is not red. I would think
this is at risk as well as 1 week from "Later this week" is
around Aug 6th.


Also, on the My Work tab when you accept a new Work Item in your inbox
and select Plan For, you get options like "Later this Week",
"Tomorrow", "Next Week", "2 weeks".

What determines which ones appear here and are they modifiable to put
what you want?

Thanks in advance.