 Based on the provided data, here are some potential root causes for performance issues in the process:

1. Multiple approval levels: The process requires multiple approvals (from Administration, Budget Owner, Supervisor, and Pre-approver), which can cause delays and decrease performance. This is evident in the variants where an additional approval step is present (from Budget Owner or Pre-approver), as they generally have higher performance times.
2. Rejections leading to multiple resubmissions: A significant number of process variants involve rejections by approvers, leading to employees resubmitting the declaration multiple times. This back-and-forth can considerably increase the performance times, as seen in variants where there are multiple rejections before final approval.
3. Missing approvers: In some cases, there are declinations due to missing approvers. This disrupts the workflow and causes unnecessary delays in the overall process.
4. Saved but not submitted declarations: Some employees save declarations but do not submit them, leading to inefficiencies in the process. This is evident in the process variant where a declaration is saved but not submitted, resulting in a performance time of 0.000.
5. High volume of declarations: The high frequency of process execution, particularly for the first few variants, could also contribute to performance issues. With a high volume of declarations to process, the admin and approval functions may become overwhelmed, leading to delays.