Dear scheduling researcher,
We are delighted to announce the talk given by Maurice Queyranne (Sauder
School, UBC).
The title is "On Polyhedral Approaches to Scheduling Problems".
The seminar will take place on Zoom on Wednesday, June 22 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/91083429684?pwd=QlJXcHB4dGtLdE40b1hGaEVMbTNFdz09
Meeting ID: 910 8342 9684
Passcode: 190280
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
The formulation of scheduling problems as mathematical optimization
problems is a useful step in deriving exact solutions, or approximate
solutions with performance guarantees. We give a brief overview of
polyhedral approaches, which aim to apply the power of linear and
mixed-integer optimization to certain classes of scheduling problems, in
particular those with min-sum type of objectives such as to minimize
weighted sums of completion dates. The choice of decision variables is
the prime determinant of such formulations. Constraints, such as facet
inducing inequalities for corresponding polyhedra, are often needed, in
addition to those just required for the validity of the initial
formulation, in order to derive useful dual bounds and structural
insights. Alternative formulations are based on various types of
decision variables, such as: start date and completion date variables,
that simply specify when a task is performed; linear ordering variables,
that prescribe the relative order of pairs of tasks; traveling salesman
variables, which capture immediate succession of tasks and changeovers;
assignment and positional date variables, which specify the assignment
of tasks to machine or to positions; and time-indexed variables which
rely on a discretization of the planning horizon, in particular machine
switch-on and switch-off variables in production planning and unit
commitment in power generation. We point out relationship between
various models, and emphasize the role of supermodular polyhedra and
greedy algorithms.
The next talk in our series will be in September.
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Nicole Megow (Universität
Bremen).
The title is "Learning-Augmented Online Algorithms for Scheduling and
Routing".
The seminar will take place on Zoom on Wednesday, June 8 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/93281103550?pwd=ckU0dWRRYWFUb2tRV2duakRjMVgyZz09
Meeting ID: 932 8110 3550
Passcode: 197150
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Online optimization refers to solving problems where an initially
unknown input is revealed incrementally, and irrevocable decisions must
be made not knowing future requests. The assumption of not having any
prior knowledge about future requests seems overly pessimistic. Given
the success of machine-learning methods and data-driven applications,
one may expect to have access to predictions about future requests.
However, simply trusting them might lead to very poor solutions, as
these predictions come with no quality guarantee. In this talk we
present recent developments in the young line of research that
integrates such error-prone predictions into algorithm design to break
through worst case barriers. We discuss different prediction models and
algorithmic challenges with a focus on online scheduling and routing and
give an outlook to network design problems.
The next talk in our series will be given by:
Maurice Queyranne (Sauder School, UBC)| June 22 | On Polyhedral
Approaches to Scheduling Problems
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Stanislaw Gawiejnowicz
(AMU Poznañ).
The title is "Past, present and future of time-dependent scheduling".
The seminar will take place on Zoom on Wednesday, May 25 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/91521949771?pwd=a091cWhwY1RzUGdYck9QeFd3d29vQT09
Meeting ID: 915 2194 9771
Passcode: 759526
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
In the lecture, we will present a general landscape of time-dependent
scheduling which is one of the main research domains in modern
scheduling theory. This lecture will be divided into three parts. In the
first part, we will sketch the main dates in time-dependent scheduling
development, specify the most important forms of time-dependent
processing times and formulate the basic assumptions of time-dependent
scheduling. Next, we will present the main results from that area,
paying a special attention to applied proof techniques and mutual
relations between different time-dependent scheduling problems. Finally,
we will discuss selected open problems in time-dependent scheduling,
summarizing known results for each open problem and indicating possible
ways of its further research.
The next talk in our series will be given by:
Nicole Megow (Universität Bremen) | June 8 | Scheduling under Uncertainty
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Patrick De Causmaecker
(KU Leuven).
The title is "Data Science Meets Scheduling".
The seminar will take place on Zoom on Wednesday, May 11 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/99017304143?pwd=N2VaLzlWT2FWTlFaamNQWkV1N2UrZz09
Meeting ID: 990 1730 4143
Passcode: 922592
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
The impact of techniques from data science and machine learning on
scheduling is investigated. We review a number of recently emerged
applications of these techniques that can shed a new light on
combinatorial optimization in general. We give concrete examples for
scheduling in particular. We distinguish on-line techniques, that is,
data science techniques integrated into advanced algorithms, off-line
techniques which can be used to improve, select of construct algorithms
as well as techniques that consider the problem as living in a space of
which the dimensions are set by specific properties of its instances. We
give examples of recent results obtained for specific problems in the
scheduling domain. Meeting works in two directions. We give an example
where a recent theoretical result for a combinatorial optimization
problem provides new insights in the structures on which the data
science techniques can operate. In this case, the theoretical result
allowed to locate a region of hard problem instances in the instance space.
The next talk in our series will be given by:
Stanislaw Gawiejnowicz (AMU Poznañ) | May 25 | Past, present and future
of time-dependent scheduling
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Iiro Harjunkoski (Hitachi
Energy).
The title is "Scheduling and Energy – Industrial Challenges and
Opportunities".
The seminar will take place on Zoom on Wednesday, April 27 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/93348597561?pwd=UUNvSG1NaDhUbTBPaHpUdE9LWTNDUT09
Meeting ID: 933 4859 7561
Passcode: 354778
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Real-life industrial scheduling problems, especially in the process
industries, are very complex as they contain many problem-specific
features or rules that are sometimes even difficult to be expressed
mathematically. Nonetheless, often the requirement to reach optimality
or close-to-optimality is critical for the competitiveness and the
survival of the company. Due to this, mixed-integer linear programming
(MILP) has become the most common tool of choice and can be said to be
the "backbone" for many practical scheduling problems.
In this presentation, we take an engineering perspective of selected
problems and discuss few examples where energy plays a significant role.
The role of energy is in fact growing and most process industries will
in the future be more closely integrated into the energy supply chain.
We will discuss few MILP formulations and methods to improve their
performance in practical cases.
The next talk in our series will be given by:
Patrick De Causmaecker (KU Leuven) | May 11 | Data Science Meets Scheduling
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Pascal Van Hentenryck
(Georgia Tech).
The title is "Constraint Programming for Scheduling".
The seminar will take place on Zoom on Wednesday, April 13 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/94015623000?pwd=eThCQmZwZjJpdExEK2g0TWUvLzZuZz09
Meeting ID: 940 1562 3000
Passcode: 808863
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
This talk reviews the start of the art in solving scheduling problems
with constraint programming, and examines novel research directions,
with a focus on the integration of constraint programming and
mathematical programming, and the use of machine learning. It reviews
applications where constraint programming provides an integrated
approach to complex problems, the hybridization of constraint
programming and mathematical programming, learning-based constraint
programming, and optimization proxies.
The next talk in our series will be given by:
Iiro Harjunkoski (Hitachi Energy) | April 27 | Scheduling and Energy –
Industrial Challenges and Opportunities
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Christian Artigues (LAAS
- CNRS).
The title is "Mixed integer linear programming for resource-constrained
scheduling".
The seminar will take place on Zoom on Wednesday, March 30 at 13:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/91490324777?pwd=dFV0UjRlL2UyZUg1ZC9ZdGtJb2FqUT09
Meeting ID: 914 9032 4777
Passcode: 848529
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Mixed-Integer linear programming (MILP) is one of the generic modeling
and algorithmic solution framework for NP-hard scheduling problems,
along with Constraint Programming (CP) and SAT solvers. However, the
literature often reports poor results of MILP solvers for
resource-constrained scheduling problems compared to CP or SAT-based
approaches such as Lazy Clause Generation. However, even if this is
partly true because of the powerful dedicated scheduling algorithms
embedded in constraint propagators, MILP approaches can reach very good
results in terms of primal and dual bounds if the right formulation and
specialized MILP components such as valid inequalities and column
generation are chosen for the problem at hand. This talk first reviews
the standard MILP formulations for resource-constrained scheduling
problems and a few recent advances in the field. In particular, we focus
on basic polyhedral results, on the relative relaxation strength of
compact and extended formulations augmented with valid inequalities.
Finally, we provide examples, including industrial ones where MILP,
possibly integrated in hybrid CP/SAT/MILP methods, appears as a
technique of choice.
The next talk in our series will be given by:
Pascal Van Hentenryck (Georgia Tech) | April 13 | Constraint Programming
for Scheduling
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Lars Mönch (Uni of Hagen).
The title is "Scheduling Problems in Semiconductor Wafer Fabrication
Facilities: Part 2".
The seminar will take place on Zoom on Wednesday, March 16 at 14:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/94701637415?pwd=TWI4ZDVINUNRd3pjWktQNjFDRXJJZz09
Meeting ID: 947 0163 7415
Passcode: 919535
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Semiconductors enable the systems and products that we use to work,
communicate, travel, entertain, harness the energy, treat illness, make
new scientific discoveries, and more. Semiconductor manufacturing is
among the most complex manufacturing systems in existence today. This
complexity makes scheduling semiconductor manufacturing systems
extremely difficult.
In this two-part seminar, we discuss scheduling problems in this
challenging domain. In the second part, we discuss batch scheduling
problems, multiple orders per job scheduling problems, and scheduling
problems that include time lags for the jobs. Moreover, scheduling
problems related to cluster tools will be also briefly considered.
Solution techniques, mainly based on problem decomposition and
metaheuristics, will be also discussed. Finally, future research
direction for scheduling semiconductor wafer fabrication facilities will
be identified.
The next talk in our series will be given by:
Christian Artigues (LAAS - CNRS) | March 30 | Mixed integer linear
programming for resource-constrained scheduling
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by John W. Fowler (Arizona
State Univ.).
The title is " Scheduling Problems in Semiconductor Wafer Fabrication
Facilities: Part 1".
The seminar will take place on Zoom on Wednesday, March 2 at 14:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/96133782270?pwd=VVFGRGJoSS9IZ1d5NkRyamFiZUh5QT09
Meeting ID: 961 3378 2270
Passcode: 292650
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Semiconductors enable the systems and products that we use to work,
communicate, travel, entertain, harness energy, treat illness, make new
scientific discoveries, and more. Semiconductor manufacturing is among
the most complex manufacturing systems in existence today. This
complexity makes scheduling semiconductor manufacturing systems
extremely difficult.
In this two-part seminar, we discuss scheduling problems in this
challenging domain. In the first part, we describe the manufacturing
process and identify typical scheduling problems found in semiconductor
manufacturing systems at the workstation, work area, factory, and supply
chain levels. We also discuss approaches for scheduling problems with
secondary resources and for factory level scheduling.
The next talk in our series will be given by:
Lars Mönch (Uni of Hagen) | March 16 | Scheduling Problems in
Semiconductor Wafer Fabrication Facilities: Part 2
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/
Dear scheduling researcher,
We are delighted to announce the talk given by Kangbok Lee (POSTECH,
Korea).
The title is "Scheduling Heuristics for Steelmaking Continuous Casting
Processes".
The seminar will take place on Zoom on Wednesday, February 16 at 14:00 UTC.
Join Zoom Meeting
https://cesnet.zoom.us/j/91094063787?pwd=d01UbWRPOHJQUy93dnBhWU5QclRLQT09
Meeting ID: 910 9406 3787
Passcode: 284143
You can follow the seminar online or offline on our Youtube channel as well:
https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A
The abstract follows.
Steelmaking-Continuous Casting (SCC) is a bottleneck in the steel
production process and its scheduling has become more challenging over
time. In this paper, we provide an extensive literature review that
highlights challenges in the SCC scheduling and compares existing
solution methods. From the literature review, we collect the essential
features of an SCC process, such as unrelated parallel machine
environments, stage skipping, and maximum waiting time limits in between
successive stages. We consider an SCC scheduling problem with as
objective the minimisation of the weighted sum of cast break penalties,
total waiting time, total earliness, and total tardiness. We formulate
the problem as a mixed-integer linear programming model and develop an
iterated greedy matheuristic that solves its subproblems to find a
near-optimal solution. Through numerical experiments, we show that our
algorithm outperforms two types of genetic algorithms when applied to
test instances.
The next talk in our series will be given by:
John W. Fowler (Arizona State Univ.) | March 2 | Scheduling Problems in
Semiconductor Wafer Fabrication Facilities: Part 1
For more details, please visit https://schedulingseminar.com/
With kind regards
Zdenek, Mike and Guohua
--
Zdenek Hanzalek
Industrial Informatics Department,
Czech Institute of Informatics, Robotics and Cybernetics,
Czech Technical University in Prague,
Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic
https://rtime.ciirc.cvut.cz/~hanzalek/