Enhancements in 18.11 provided additional functionality for suspensions.  This document provides the details.

This feature allows the library to suspend a borrower’s circulation privileges for a number of days if items are returned late.  The rules for suspensions are set in Circulation and Fines Rules and applied once the items are returned.

In Circ and Fines Rules you can specify the number of days their account should be suspended in the Suspension in days field.  Please note, this can only be set for the Day unit, not in Hours.  So, if you want to suspend the account by 1 day for every day that an item is overdue, set Fine charging interval to 1 and Suspension in days (day) to 1.

You can also define the maximum number of days a patron will be suspended in the Max suspension duration field.   This applies to each overdue item, not as an overall limit on the patron record.

The system can use the calendar when setting suspension days so closed days are not included.  Set SysPref finesCalendar to Calculate fines based on days overdue not including days the library is closed if this is what you want.

If the patron has more than one item overdue and you want to allocate suspensions to each overdue item, set SysPref CumulativeRestrictionPeriods = Cumulate.  As each overdue item is returned the system will calculate the extra suspension days and extend the Suspension Expiry Date accordingly.

There is a switch in the daily cleanup task on your system to clear expired suspensions, please ask Interleaf to check it is set.  If expired suspensions are not cleared, new suspensions will be added to the last expiration date.

Points to note:

The first thing to note is that suspensions are only created when the item is returned. If you renew an overdue item the suspension that would have accrued is removed, but if it goes overdue again the suspension starts to build. The number of days the patron will be suspended will be determined by how many days the item is overdue when it is checked in. This is because the system calculates how many days the patron needs to be suspended based on how many days in total the item was overdue and this can only be calculated after it has stopped accruing overdue days.

The Suspension charging interval in Circ and Fines Rules means how many days should there be between each instance when more time is added to the suspension. Think of it like the Fine charging interval: if you charge a fine of €1 and have a fine charging interval of 1, it will charge €1 every day that elapses whilst the item is overdue. Similarly, if you have Suspension in days set to 1 and Suspension charging interval set to 3 it will suspend the patron for 1 day for every 3 days the item is overdue. So if a patron has an item out and it is 3 days overdue they will be suspended for 1 day, if it is overdue by 6 days, they will be suspended by 2 days. You can also use the Max. suspension duration (day) column to cap how many days a patron can be suspended for a single item.

There are actually a few types of suspensions/restrictions/debarments.
The overdue cron job which runs at 6am daily adds an Indefinite suspension once the book becomes overdue. This stays on the borrower account until the overdue book(s) are returned. When you look at the Restrictions tab these have a Type of OVERDUES and show Indefinite under the Expiration Date.

If you have suspensions active, when you check in the overdue book the system calculates the number of days overdue and uses this to decide how many days suspension to add. The suspension is added at the time that the item is checked in. When you look at the Restrictions tab these have a Type of SUSPENSION and show an actual Expiration Date.
The third type are those added manually by staff in the library. The suspension is added at the time that the staff member adds it. When you look at the Restrictions tab these have a Type of MANUAL and show an actual Expiration Date.

Any one borrower can only have one OVERDUES and one SUSPENSION type on their account at any given time. No matter how many overdue books you have you will just have one OVERDUES suspension with an Indefinite Expiration Date. This will stay on the account until ALL overdue items are checked in.
When the first overdue book is checked in the SUSPENSION type will be created with an actual Expiration Date. If a second overdue book is checked in the system calculates the number of days overdue and uses this to decide how many days suspension to add, it then just increments the Expiration Date on the existing SUSPENSION type. This SUSPENSION type will be cleared by another cron job after the Expiration Date has passed.

Clicking on View Restrictions will show a summary of the Suspension:

However, if you check Circulation History, and view the most recent first, you will see more details:

Some libraries have added custom reports to list suspensions, contact Interleaf Support for details.