Italy Instance 4 was provided by Andrea Schaerf. Each teacher has DD lessons: these are lessons not attached to a class, but to the school; it is to guarantee that at any time in the morning there is a teacher available. The instance was converted to XHSTT by Gerhard Post.
A lowerbound for the cost is 27:
- Class 2G has 31 times with events hence at least one event on the last hour cannot be avoided (cost 3).
- Class 3A has 32 times with events hence at least two events on the last hours cannot be avoided (cost 6).
- Class 3B has 32 times with events hence at least two events on the last hours cannot be avoided (cost 6).
- Teacher palest1 has 31 times with events hence at least one day with 6 busy times (cost 6).
- Teacher palest2 has 31 times with events hence at least one day with 6 busy times (cost 6).
A summary of the data can be found in the following table:
Assets | Times | Teachers | Rooms | Students | Classes | # events | Total duration |
value | 36 | 61 | - | - | 38 | 748 | 1101 |
The following constraints are present:
- Scheduling constraints: AssignTimeConstraint and SplitEventsConstraint.
- Event constraints: PreferTimesConstraint and SpreadEventsConstraint.
- Resource constraints: AvoidClashesConstraint, AvoidUnavailableTimesConstraint, LimitIdleTimesConstraint, ClusterBusyTimesConstraint, and LimitBusyTimesConstraint.
The following (feasible) solutions are submitted for this instance:
SolutionGroup | Objective value | Lowerbound | Submitted by | Received |
AndreaSchaerf_2009-12-02 | 84 | - | Andrea Schaerf | 2009 |
LectioIntegerProgramming | 57 | 27 | Simon Kristiansen et al | September 5, 2013 |
KHE_2014-03-12 | 56 | - | Jeffrey H. Kingston | March 12, 2014 |
KHE_2014-03-13 | 54 | - | Jeffrey H. Kingston | March 13, 2014 |
KHE_2014-05-01 | 50 | - | Jeffrey H. Kingston | May 1, 2014 |
KHE_2014-05-07 | 40 | - | Jeffrey H. Kingston | May 7, 2014 |
ArtonDorneles_fixopt | 34 | - | Árton Dorneles | August 22, 2014 |
GOAL team - Feb 12, 2015 | 28 | - | UFOP-GOAL team: Fonseca G.H.G. Santos H.G. and Carrano E.G. | February 23, 2015 |
GOAL team April 2015 | 27 | - | UFOP-GOAL team: Fonseca G.H.G. Santos H.G. and Carrano E.G. | July 20, 2015 |
XML file
ItalyInstance4.xml (instance and solutions)
ItalyInstance4.xml (XHSTT2013)
[Update to 2014: cost function simplified.]
[Update, January 6, 2014: A small glitch has been corrected, using ClusterBusyTimesConstraint (Id="ClusterBusyTimesConstraint_1") instead of previously LimitBusyTimesConstraint (Id="MinNofHoursPerDayConstraint_14").]