Begin of the insertion## User Story

End of the insertion **As** a _plugin developer,_
**I Begin of the insertionneed** specific hooks in the service implementation\_,\_
**so that** I am _ableEnd of the insertion Begin of the deletion want to** _be ableEnd of the deletion to Begin of the deletion automaticallyEnd of the deletion calculate Begin of the insertionthe values of custom fields automaticallyEnd of the insertion Begin of the deletion and rank work packagesEnd of the deletion based on Begin of the deletion custom fieldEnd of the deletion values Begin of the insertionof other custom fields of one or more work-packages._End of the insertion Begin of the deletion using a plugin,_
**so that** _I can quickly identify high-priority work packages_End of the deletion

**Acceptance criteria**

* Begin of the insertionhooks for creation, updating and deletion of work-packages

## Context information of the current impementation of the plugin

* End of the insertion The Begin of the insertionhooks are already in our core implemenation. **A pull request can be created.**
* TheEnd of the insertion plugin should allow the user to specify a formula for calculating the custom field values.
* The plugin should automatically update a custom field with the calculated value for each work package whenever a custom field (added to the formula) is updated or a new work package is created.
* The plugin should automatically update the ranking of each work package based on the updated custom field with the calculated value whenever a custom field (added to the formula) is updated or a new work package is created.
* Begin of the insertionTheEnd of the insertion Begin of the deletion  TheEnd of the deletion plugin should also update the ranking of each work package when a work package is deleted.
* The plugin should provide a user-friendly interface for managing custom fields and configuring the calculation formula.