DMP87 - Scheduling, Timetabling and Routing
Weekly Notes
Lecture 2, Fall 2008

Lecture January 31

We discussed complexity hierarchies in scheduling. In particular we focused on the distinction NP-hard in ordinary sense, that is, pseudo-polynomially solvable, and NP-hard in the strong sense. This distinction arises in number problems such as the Partition problem. We described a pseudo-polynomial time algorithm for the Partition problem and defined the 3-Partition problem which is NP-complete in the strong sense. Treatment of this part can be found in Appendix C of [2] and on pages 90-106 of [1].

We then treated CPM/PERT which can be read from the text book on pages 52 through 61.

The second part of the lecture was aimed at giving an introduction to Linear and Integer Programming. This can be read from the Appendix A of the text book or from the slides which were mainly based on a course by Martin Grötschel (Technische Universität Berlin).

The next lecture we will see MIP formulations and introduce constraint programming. Reading material Appendix D of the text book.

Bibliography

1
M. R. Garey and D. S. Johnson.
Computers and Intractability: A Guide to the Theory of ${\cal
NP}$-Completeness.
Freeman, San Francisco, CA, USA, 1979.

2
M.L. Pinedo.
Scheduling: Theory, Algorithms, and Systems.
Prentice Hall, second edition, 2002.

Assignments

Exercise 1

Consult the web site about complexity hierarchies in scheduling:

http://www.mathematik.uni-osnabrueck.de/research/OR/class/

Exercise 2

Consult the following web site about Mathematical Programming http://www-neos.mcs.anl.gov/

Exercise 3

Solve the following instance of $P2\vert\vert C_max$ with a pseudo-polynomial algorithm:


\begin{displaymath}
\begin{array}{rrrrrr}
jobs&1&2&3&4&5\\
\hline
p_j&7&8&2&4&1
\end{array}\end{displaymath}



Marco Chiarandini 2008-01-31