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").]